QE 


•TUDIES  IN  GEOLOGY 


A  LABORATORY  MANUAL  BASED  ON  TOPOGRAPHIC 

MAPS  AND  FOLIOS  OF  THE  UNITED  STATES 

GEOLOGICAL  SURVEY,  FOR  USE  WITH 

CLASSES  IN  PHYSIOGRAPHIC  AND 

STRUCTURAL  GEOLOGY 


BY 
ROLLIN  D.  SALISBURY 

THE  UNIVERSITY  OP  CHICAGO 


AND 


ARTHUR  C.  TROWBRIDGE 

THE   UNIVERSITY  OP  IOWA 


NEW  YORK 

HENRY  HOLT  AND  COMPANY 
1912 


COPYRIGHT,  1912 

BY 
HENRY  HOLT  AND  COMPANY 


THE. MAPLE. PKESS. YORK. PA 


PREFACE 

This  manual  is  a  combination  of  the  exercises  now  in 
use  in  the  laboratories  of  the  authors,  with  students  of 
somewhat  advanced  grade.  It  is  offered  to  teachers  and 
students  in  the  belief  that  a  clear  understanding  of  topo- 
graphic maps  contributes  in  an  important  way  to  a  thorough 
knowledge  of  Physiography  and  physiographic  geology,  and 
that  the  use  of  these  maps  should  be  carried  far  enough  to 
make  them  almost  as  familiar  as  the  printed  page.  It  is 
hoped  that  the  manual  may  be  useful  to  students  who  are 
under  the  direction  of  teachers  who  are  familiar  with 
modern  methods  of  laboratory  work  in  physiography  and 
physical  geology,  as  well  as  to  those  who  are  not  so  fortunate. 
The  subject  involved  is  not  inherently  difficult  and  may  be 
mastered  by  any  serious  student,  whether  he  be  pupil  or 
teacher,  or  altogether  independent  of  schools. 

The  work  is  based  on  topographic  maps  (and  a  few 
folios)  of  the  United  States  Geological  Survey,  and  on  a 
key  to  the  interpretation  of  topographic  maps,1  published 
by  the  same  survey.  It  is  intended  for  the  use  of  students 
how  have  some  knowledge  of  physiography,  or  who  are  suffi- 
ciently mature  to  take  up  the  subject  in  a  somewhat  thorough- 
going way.  It  might  well  be  used,  for  example,  by  students 
using  Chamberlin  and  Salisbury's  Geology,  Vol.  I  (Geologic 
Processes)  for  a  text.  While  the  outline  follows  the  general 
order  of  this  text,  it  may  be  adapted"  to  courses  based  on 
any  other  standard  text  of  similar  scope.  This  outline, 
based  chiefly  on  topographic  maps,  is  followed  by  another 

1  Professional  Paper  60,  U.  S.  Geol.  Surv. 

iii 

258013 


iv  PREFACE 

for  students  of  similar  grade  based  on  folios  of  the  U.  S 
Geological  Survey,  and  intended  for  use  in  thorough- 
going courses  on  Historical  Geology,  such  as  those  based 
on  Volumes  II  and  III  of  Chamberlin  and  Salisbury's 
Earth  History. 

The  adaptation  of  this  outline  to  the  needs,  the  time,  the 
laboratory  facilities,  and  the  amount  of  laboratory  assistance 
available,  must  be  left  to  the  individual  teacher,  but  two 
methods  of  procedure  which  have  been  used  successfully 
are  here  outlined.  (1)  By  the  one  method,  the  class  is 
divided  into  sections  of  four  students  each.  The  assign- 
ment of  an  exercise  is  made,  and  the  maps  placed  where 
the  students  may  study  them  at  their  convenience.  An 
hour  for  conference  with  the  instructor,  subsequent  to  the 
study  of  the  maps,  is  assigned  to  each  section.  In  these  con- 
ferences, the  topic  illustrated  by  the  maps  assigned  is  dis- 
cussed, in  connection  with  the  maps.  After  the  conference, 
or  in  some  cases  before,  designated  questions  are  answered  in 
writing,  and  the  papers  handed  to  the  instructor  for  cor- 
rection. (2)  By  the  other  method,  definite  laboratory 
periods  are  assigned,  their  duration  and  frequency  being 
determined  by  the  time  and  general  plan  of  the  course,  and 
the  degree  of  preparation  of  the  students.  All  the  work  is 
done  in  the  laboratory  in  the  presence  of  the  instructor  or 
his  assistants.  The  students  work  individually  or  in  pairs, 
and  receive  help  or  criticism  from  the  instructor  on  demand. 
The  latter  method  is  the  more  successful  with  younger 
students,  where  time,  laboratory  space,  assistance,  and 
supply  of  maps  are  sufficient;  but  the  first  is  perhaps  equally 
successful  with  advanced  students.  The  laboratory  exercise 
with  the  maps  follows  .the  class-room  discussion  of  the  topic 
involved. 


PREFACE  v 

One  or  two  conferences,  following  the  study  of  the  maps 
by  the  students,  to  five  hours  of  class-room  work  are  recom- 
mended; but  this  ratio  may  be  varied  ad  libitum.  When 
practicable,  it  is  much  better  to  have  the  laboratory  work 
follow  the  class-room  discussion  of  the  same  topic  immedi- 
ately, rather  than  to  have  the  laboratory  work  on  certain 
fixed  days. 

One  copy  of  each  map  for  every  six  or  eight  students  in 
the  class  is  sufficient.  The  maps  should  be  backed  with 
cloth  to  avoid  speedy  destruction,  though  a  few  maps 
should  be  unbacked,  for  the  sake  of  the  printed  matter 
on  the  back.  In  a  few  cases,  too,  important  illustrative 
material  appears  on  the  back  of  the  map,  as  in  the  case  of 
the  Crater  Lake,  Ore.,  sheet. 

Should  it  be  desirable  to  develop  a  course  of  study  beyond 
that  called  for  by  this  outline,  the  maps  and  charts  listed 
at  the  end  of  each  exercise  are  recommended  as  a  basis. 

Thanks  are  due  Professors  W.  W.  Atwood  and  H.  H. 
Barrows  for  free  use  of  laboratory  outlines  in  which  their 
work  is  represented. 


STUDIES  IN  PHYSIOGRAPHY 


EQUIPMENT 

Topographic  Maps1 

ALABAMA  CALIFORNIA 

Fort  Payne  Cayucas 

Cucamonga 

ARIZONA  Haywards 

Bright  Angel  Honey  Lake 

Diamond  Creek  La  Jolla 

Echo  Cliffs  Lassen  Peak 

Mt.  Trumbull  Marysville 

Parker  Maxwell 

San  Francisco  Mt.  Mt.  Lyell 

Tusayan  Mt.  Whitney 

ARKANSAS  Oceanside 

Batesville  San  Francisco 

Marshall  San  Jose 

Morrillton  San  Mateo 

Mountain  View  Shasta 

Shasta  Special 

CALIFORNIA  Sierraville 

Bridgeport  Sutter 

1  These  maps  may  be  ordered  from  the  Director  of  the  United 
States  Geological  Survey,  Washington,  D.  C.  All  except  a  few 
special  and  double  sheets  may  Lbe  had  for  3  cents  each,  if 
ordered  in  lots  of  100  or  more. 

1 


2  STUDIES  IN  GEOLOGY 

CALIFORNIA  ILLINOIS 

Tamalpais  New  Haven 

Yosemite  Tallula 

Wheaton 

COLORADO 

Apishapa  INDIANA 

Denver  Boonville 

Elmoro  Owensboro 

Leadville  Patoka 

Mesa  de  Maya  Princeton 

Montrose  Toleston 

Mount  Jackson  r^™  A 

o        •  u  T>     i  IOWA 

Spanish  reaks 

^  ,       ,  Cordova 

Walsenburg; 

Des  Monies 

CONNECTICUT  Durant 

Hartford  Fairfax 

FLORIDA  Marion 

Tsala  Apopka  Oelwein 

Williston  Savanna 

Waukon 

IDAHO 

Bisuka  KANSAS 

Meadows  Anthony 

Mountain  Home  Burlingame 

Coldwater 

ILLINOIS  Dodge 

Dunlap  Emporia 

Elizabeth  Fredonia 

Hennepin  Great  Bend 

High  wood  Kinsley 

La  Salle  Lakin 

Marseilles  Leavenworth 


STUDIES  IN  GEOLOGY 


KANSAS 
Pratt 
Spearville 
Syracuse 

KENTUCKY 

Dawson  Springs 

Harrodsburg 

Jonesville 

Lockport 

London 

Princeton 

Saylersville 

Tell  City 

LOUISIANA 

Baton  Rouge 
Donaldsonville 
Gibson 
Hahnville 
New  Orleans 

MAINE 

Castine 

Freeport 

Fryeburg 

Gray 

Portland 

MARYLAND 

Antietam 


MARYLAND 
Choptank 
Emmitsburg 
Flintstone. 
Ocean  City 
Pawpaw 
Prince  Frederick 
Tol  chester 

MASSACHUSETTS 
Boston 
Falmouth 
Holyoke 

Marthas  Vineyard 
Nantucket 
Provincetown 
Wellfleet 

MICHIGAN 

Calumet  Special 

MINNESOTA 
Minneapolis 
Minnetonka 
St.  Paul 

MISSOURI 

Boonville 

Forsyth 

Fulton 

Glasgow 

Hermann 


STUDIES  IN  GEOLOGY 


MISSOURI 

Independence 
Jefferson  City 
Lexington 
Marshall 
St.  Louis 
Tuscumbia 

MONTANA 

Chief  Mountain 

Hamilton 

Saypo 

NEBRASKA 

Browns  Creek 
David  City 
Lexington 
North  Platte 
Whistle  Creek 

NEVADA 

Hawthorne 
Silver  Peak 

NEW  HAMPSHIRE 
Monadnock 

NEW  JERSEY 
Asbury  Park 
Atlantic  City 
Barnegat 
Cape  May 


NEW  JERSEY 

Greenwood  Lake 
Long  Beach 
High  Bridge 
Passaic 
Sandy  Hook 

NEW  MEXICO 
Corazon 
Mt.  Taylor 

NEW  YORK 

Brooklyn 

Cohoes 

Cooperstown 

Elmira 

Hammondsport 

Islip 

Kaaterskill 

Monticello 

Niagara 

Oak  Orchard 

Palmyra 

Paradox  Lake 

Penn  Yan 

Phelps 

Rosendale 

Skaneateles 

Sodus  Bay 

Staten  Island 

Syracuse 

Tully 


STUDIES  IN  GEOLOGY 

NEW  YORK  PENNSYLVANIA 
Watkins  Erie 

Weedsport  Everett 

NORTH  CAROLINA  Fairview 

T  .       ,  Jb  oxburg 

Lincolnton 

Mt.  Mitchell  "amb"rS 

_..  Hamsburg 

Pisgah 

Masontown 

NORTH  DAKOTA 

Casselton  SOUTH  CAROLINA 
Fargo  Abbieville 

Pingree 

OHIO  SOUTH  DAKOTA 

Cleveland  Elk  Point 


TENNESSEE 

East  Cincinnati  T,         .„ 

„,     ..  Knoxville 

Oberlm  ^..  ,  .  . 

TT1    .  ,      .„  Maynardville 

Uhricnsville  _,  *  . 

„,    .  ™     .       ..  Momstown 

West  Cincinnati  ,. 

btandingstone 

OKLAHOMA 

Salhsaw 

0       ,    .  Palo  Pinto 

bansbois  ,T     .  , 

Uvalde 

OREGON  Van  Horn 

Coos  Bay 
Crater  Lake  Special  UTAH 

Port  Orford  AbaJ° 

Fish  Springs 

PENNSYLVANIA  Gilbert  Peak 

Bellefonte  Hayden  Peak 

Brownsville  Henry  Mountains 

Delaware  Water  Gap  La  Sal 


6  STUDIES  IN  GEOLOGY 

VIRGINIA  WISCONSIN 

Abingdon  Briggsville 

Fredericksburg  Cross  Plains 

Grundy  Delavan 

Harpers  Ferry  Denzer 

Natural  Bridge  Special  Geneva 

WASHINGTON  Koshkonong 

Lancaster 
Chelan  ^T  j- 

Madison 
Glacier  Park  ^/r     i 

Muskego 
Methow  ^ 

Uconomowoc 
Mount  Stuart  Radne 

^tehekm  St.  Croix  Dalles 

Stoughton 

WEST  VIRGINIA  The  Dells 

Arnoldsburg  Waterloo 

Fayetteville  Wausau 

Madison  Whitewater 
Peytona 

Point  Pleasant  WYOMING 

Canyon 

WISCONSIN  Cloud  Peak 

Baraboo  Grand  Teton 

Geologic  Folios1 

Bristol,  Va.  Masontown-Uniontown,  Pa. 

Camp  Clarke,  Nebr.  Norfolk,  Va. 

Chattanooga,  Tenn.  Piedmont,  W.  Va.-Md. 

Franklin,  W.  Va.-Va.  Pikesville,  Tenn. 

Kingston,  Tenn.  Rome,  Ga. 
Livingston,  Mont. 

1  These  folios  may  be  obtained  from  the  Director  of  the  United 
States  Geological  Survey,  Washington,  D.  C.;  for  25  cents  per  copy. 


STUDIES  IN  GEOLOGY  7 

Charts 

Coast  Survey  Charts,1  Nos.  19,  21,  103,  104,  105,  5100, 
5143,  8089. 

Lake  Michigan  Chart,2  No.  5. 

Maps  and  Models 

Students  should  have  free  access  to  good  maps  of  the 
United  States,  when  working  on  the  topographic  maps.  A 
good  wall  map,  showing  political  boundaries  and  relief,  and 
if  possible  a  good  relief  model  should  be  in  the  laboratory. 

Reference  Material3 

The  Interpretation  of   Topographic  Maps,  Salisbury  and 
Atwood;  Prof.  Paper  60,  U.  S.  Geol.  Surv.4 
The  text-books  used  in  the  course. 
Bull.  No.  13,  Illinois  Geol.  Surv. 
Bull.  No.  V,  Wis.  Geol.  and  Nat.  Hist.  Surv. 
Bull.  No.  XIII,  Wis.  Geol.  and  Nat.  Hist.  Surv. 
Mono.  XI,  U.  S.  Geol.  Surv. 
Mono.  II,  U.  S.  Geol.  Surv. 

GENERAL  DIRECTIONS 

In  the  case  of  each  set  of  maps  assigned,  observe  the 
following  general  outline: 

1  These  charts  may  be  had  of  the  Coast  and  Geodetic  Survey, 
Washington,  D.  C. 

2  This  chart  may  be  had  of  the  United  States  Northern  and 
Northwestern  Lake  Survey,  Washington,  *D.  C. 

3  These  materials  for  reference  should  be  open  to  the  students 
in  the  laboratory  or  near-by  library  at  all  times. 

*  This  report  may  be  had  upon  request  to  the  Director  of  the 
United  States  Geological  Survey,  Washington,  D.  C.,  so  long  as  it 
remains  in  stock. 


8  STUDIES  IN  GEOLOGY 

1.  Study  with  care  all  the  maps  assigned,  according  to  the 
directions  and  questions  presented  with  them. 

2.  In  studying  a  map,  notice  at  the  outset: 

a)  The  location  of  the  region  represented. 

b)  The  contour  interval. 

c)  The  horizontal  scale. 

d)  The  date  when  the  region  was  surveyed. 

3.  Be  able  (or  try  to  be)  to  answer  all  questions  of  the 
outline,  and  answer  in  writing  those  marked  *. 

4.  Make  answers   concise  and  to  the  point.     In    some 
cases  a  word  will  suffice,  in  others  a  sentence,  and  in  still 
other  cases,  full  and  carefully  written  statements  are  needed. 

5.  After   the    corrected    paper   is    returned,    review   the 
exercise  with  the  maps,  in  order  to  see  just  where  mistakes 
were  made. 

6.  Keep  the  main  physiographic  provinces  of  the  United 
States  constantly  in  rnind,  and  note  the  province  to  which 
each  map-area  studied,  belongs.     (See  Exercise  XVII.) 


I.  THE  WORK  OF  THE  WIND 
I.  ASSIGNMENT 

a)  Topographic  Maps 

Asbury  Park,  N.  J.  Long  Beach,  N.  J. 

Barnegat,  N.  J.  North  Platte,  Neb. 

Browns  Creek,  Neb.  Pratt,  Kan. 

Cape  May,  N.  J.  Sandy  Hook,  N.  J. 

,   Dodge,  Kan.  Spearville,  Kan. 

„«]       Great  Bend,  Kan.  Syracuse,  Kan. 

Kingsley,  Kan.  Toleston,  Ind. 
Whistle  Creek,  Neb. 

b)  Geologic  Folios 

Camp  Clarke,  Neb.^          Norfolk,  Va.  *  * 

II.  OUTLINE  FOR  STUDY 

*1.  Describe  the  dunes  shown  on  the  New  Jersey  sheets, 
as  to 

a)  Distribution.  c)   Shape. 

b)  Size.  d)  Source  of  sand. 
*2.  a)  Compare  the  dunes  shown  on  the  Barnegat  sheet, 

with  those  on  Sandy  Hook  (Sandy  Hook  sheet). 

b)  How  are  elongate  dunes  formed  ?  Do  they  repre- 
sent (possibly,  probably,  certainly,)  a  later  stage  of  dune 
development  than  the  more  common  hillock  or  mound 
type  ?  Explain. 

3.  What  possible  explanation  may  there  be  for  the  mound 
type  of  dunes  southwest  of  Holly  Beach  (Cape  May  sheet), 

9 


10  STUDIES  IN  GEOLOGY 

and  the  elongate  dunes  northeast  of  the  same  place  ?  Is 
there  any  suggestion  that  the  sandy  bar  southwest  of  Holly 
Beach  is  of  more  recent  origin  than  that  to  the  northeast  ? 

4.  a)   Locate  the  dunes  on  the  topographic  map  of  the 
Norfolk  folio;  then  consult  the  areal  geology  sheet. 

*b)  What  is  the  height  of  the  highest  dune  shown  on  the 
maps  of  this  folio  ?  (Determination  to  be  as  accurate  as 
possible,  and  the  amount  of  possible  error  to  be  stated.) 

5.  Explain  the  distribution  of  the  dunes  shown  on  the 
Syracuse  sheet;  on  the  Pratt  sheet. 

\  Q.  What  sort  of  rock  would  you  expect  (How  confidently  ?) 
toTfind  directly  underlying  the  surface  of  the  dune  area  of 
the  Pratt  region  ?  Why  ? 

*7.  Give  a  brief  summary  concerning  the  dunes  of  the 
Kansas  region,  indicating  their  height,  shape,  distribution, 
and  source  of  sand. 

8.  Can  you  suggest  any  reason  why  the  dunes  of  the 
Kansas  region  are,  in  general,  higher  than  those  of  the 
Atlantic  Coast  ? 

*9.  Work  out  and  state  a  rule  expressing  the  amount  of 
possible  error  in  reading  differences  in  elevations  of  two 
points  from  contour  maps,  (a)  when  neither  point  is  on  a 
contour  line,  (b)  when  one  of  the  points  is  on  a  contour  line, 
(c)  when  both  points  are  on  contour  lines.  Illustrate  from 
selected  specific  points  on  one  of  the  maps  of  the  assigned 
list. 

10.  Camp  Clarke  Folio: 

a)  On  the  topographic  sheet,  locate  areas  of  sand 
dunes,  and  several  topographic  features  probably  not  due 
primarily  to  the  wind. 

b)  Test  the  conclusions  of  a)   by  reference  to  the 
Areal  Geology  Sheet. 


STUDIES  IN  GEOLOGY  11 

c)  The  character  of  the  Arikaree  Formation  ?     See 
pp.  2  and  3  of  the  folio  text. 

d)  What  is  the  source  of  the  sand  for  the  dunes  ? 

e)  Note  the  depressions  among  the  dunes,  shown  by 
depression  contours. 

f)  Study  the  illustration  sheet  for  evidences  of  wind 
erosion.     Explain  the  origin  of  Smokestack  Rock. 

g)  Do  you  find  any  signs  of  wind  erosion  on  the  topo- 
graphic sheet  ? 

*11.  What  can  be  said  of  the  probable  source  or  sources 
of  sand  in  Nebraska,  as  suggested  by  the  Nebraska  maps  ? 

*12.  Give  several  possible  explanations  for  the  formation 
of  such  depressions  as  are  found  among  the  dunes  in  the 
Kansas  and  Nebraska  regions. 

13.  How  could  dunes  be  recognized  in  the  field,  after 
they  are  covered  with  vegetation  ? 

14.  \Vhy  are  the  dunes  on  the  Pacific  Coast  not  shown  on 
the  topographic  maps  ? 

15.  Describe  the  general  principles  governing  the  dis- 
tribution of  sand  dunes  in  the  United  States,  so  far  as  illus- 
trated by  these  maps. 

16.  Loess  deposits  and  the  abrasive  work  of  the  wind 
cannot  be  illustrated  satisfactorily  on  topograpic  maps. 

For  more  extended  study,  the  following  additional  maps 
and  folios  are  suggested: 

Chappell,  Neb.,  sheet.  Kingman,  Kan.,  sheet. 

Fire  Island,  N.  Y.,  sheet.         Lakin,  Kan.,  sheet. 
Green  Run,  Md.  sheet.  Scotts  Bluff,  Neb.,  folio. 

Hutchinson,  Kan.,  sheet.          Springfield,  Colo.,  sheet. 


II.  THE  WORK  OF  GROUND  WATER 
I.  ASSIGNMENT 

a)  Topographic  Maps 

Jonesville,  Ky.  Natural  Bridge,  Va. 

Knoxville,  Tenn.  Princeton,  Ky. 

London,  Ky.  Standingstone,  Tenn. 

Maynardville,  Tenn.  Tsala  Apopka,  Fla. 

Morristown,  Tenn.  Williston,  Fla. 

b)  Geologic  Folios 

Bristol,  Va.  Kingston,  Tenn. 

H.  OUTLINE  FOR  STUDY 

*1.   Give  exact  locations  of  topographic  features  due  to 
ground  water,  shown  on  each  of  these  maps. 

*2.  a)   Describe   the   sinks   shown   on   the   Standingstone 
sheet,  as  to  depth,  shape,  size,  and  topographic  position. 
b)  What  sort  of  rock  would  you  expect  to  find  beneath 
them? 

3.  What  may  ground  water  have  had  to  do  with  the  for- 
mation of  the  basin  of  Tsala  Apopka  Lake  (Tsala  Apopka 
sheet)  ?  Note  the  general  topography  of  the  region. 

*4.   Choose  a   map  from  the   assigned  list  which  shows 
"Karst"  topography. 

*5.  Bristol  Folio: 

a)  From  the  topographic  map,   locate  and  describe 
briefly  the  sinks. 

b)  Explain  why  the  sinks  occur  only  in  parallel  lines. 
In  answering  this,  study  the  structure  section  sheet. 

12 


STUDIES  IN  GEOLOGY  13 

*6.  a)  Are  limestone  sinks  more  common  in  flattish 
regions,  or  in  rough  ones  ?  Why  ? 

b)  In  what  stage  of  an  erosion  cycle  would  you  expect 
limestone  sinks  to  be  more  common  ? 

*7.  Work  out  in  detail  the  probable  history  of  "Grassy 
Cove"  in  the  northwestern  part  of  the  area  shown  on  the 
topographic  map  of  the  Kingston  folio.  Consult  the  geo- 
logic map  and  text  of  the  folio. 

*8.  Study  the  Natural  Bridge  sheet  for  effects  of  the  work 
of  ground  water. 

a)  Note  the  numerous   sinks  throughout  the   region. 

b)  Explain  the  peculiar  valley  of  Cedar  Creek  in  Short 
Hills  (central  rectangle). 

c)  From  the  map,  trace  the  history  of  the   Natural 
Bridge  of  Virginia. 


THE  WORK  OF  RUNNING  WATER 

III.  STAGES  OF  VALLEY  DEVELOPMENT 
I.  ASSIGNMENT 

a)   Topographic  Maps 

Abajo,  Utah.  Highwood,  111. 

Bisuka,  Idaho. J  Leavenworth,  Kan. 

Bright  Angel,  Ariz.  *'  Lexington,  Neb. 

Brownsville,  Pa.  Marshall,  Mo. 

Canyon,  Wyo.  Masontown,  Pa. 

Cross  Plains,  Wis.  Montrose,  Colo. 

Des  Moines,  la.  Oak  Orchard,  N.  Y. 

Dunlap,  111/-1  Patoka,  Ind. 

East  Cincinnati,  Ohio.  Peytona,  W.  Va. 

Elizabeth,  111.  Tallula,  111. 

^  Elk  Point,  S.  D.  Uhrichsville,  Ohio. 

Fargo,  N.  D.  ~  Waterloo,  Wis. 
Waukon,  la. 

II.  OUTLINE  OF  STUDY 

1 .  In  what  stages  of  development  are  the  following  valleys : 

a)  Black  Canyon    (N.    E.    corner,    Montrose   sheet)? 

b)  Valley  of  Kanawha  River  (N.  E.  corner,  Peytona 
sheet)  ? 

c)  Valley   of   Missouri   River    (Leavenworth   sheet)  ? 

2.  The  age  of  the  valleys  shown  on  the  Fargo  sheet? 
Why  are  they  so  crooked  ? 

3.  Give  possible  explanation  for  the  abnormally  shaped 

14 


STUDIES  IN  GEOLOGY  15 

valley  of  the    Mississippi    River,   shown  on   the   Waukon 
sheet. 

*4.  Account  for  the  type  of  valley  found  in  the  Abajo 
region. 

*5.  Account  for  the  great  difference  in  the  sizes  of  the 
valley  shown  on  the  eastern  portion  of  the  Dunlap  sheet. 

*6.  From  maps  of  the  assigned  list,  other  than  those  desig- 
nated in  earlier  questions,  select  one  valley  in  youth,  one  in 
maturity,  and  one  in  old  age,  and  state  why  they  were  chosen. 
Locate  these  valleys  precisely  (by  name  of  map,  location  on 
map,  and  name  of  valley). 

*7.  Draw  cross-sections  across  the  three  valleys  chosen  in  6. 
Use  a  horizontal  scale  the  same  as  that  of  the  map,  and  a 
vertical  scale  of  J  inch  to  20  feet.  State  precise  location  of 
each  cross-section. 

*8.  Not  using  valleys  designated  above,  name  five  other 
youthful  valleys  shown  on  the  maps,  five  mature  valleys 
and  five  valleys  in  old  age. 

*9.  Account  for  the  great  difference  in  the  character  of 
the  valley  of  the  Yellowstone  River  and  its  tributaries  south 
of  44°  50',  on  the  Canyon  sheet. 

*10.  How  is  the  single  conspicuous  stream  (Snake  River) 
in  the  region  about  Bisuka  to  be  explained  ? 

11.  What  differences  do  the  maps  show  between  youthful 
valleys  in  plateaus  and  in  plains  ? 

*12.  Compare  and  contrast  the  history  of  the  valleys 
shown  on  the  Highwood  and  Oak  Orchard  sheets. 

13.  Some  of  the  maps  show  complete  or  nearly  complete 
tributary  river  systems.  Using  such  maps,  compare  briefly 
the  topographies  of  the  upper  and  lower  portions  of  the 
same  river  basins.  Study  examples  enough  to  warrant  a 
generalization.  *Make  the  generalization. 


16  STUDIES  IN  GEOLOGY 

Additional  material  on  valleys  may  be  obtained  from 
almost  any  topographic  map,  though  obviously  some  maps 
are  better  than  others  for  the  illustration  of  this  topic.  The 
more  recent  maps  are  always  more  desirable  than  older  ones. 
In  addition  to  those  of  the  assignment  above,  the  following 
maps,  published  recently,  show  various  stages  in  valley 
development,  and  may  be  used  for  further  work  on  the 
subject: 

Baton  Rouge,  La.  Lockport,  Ky. 

Bayou  Sara,  La.  Monticello,  N.  Y. 

Central  City,  Ky.      .        Natural  Bridge,  Va. 

Covington,  Ohio.  Ottawa,  Ohio. 

Cumberland,  Ohio.  Oxford,  Ohio. 

Franklin,  Pa.  Ravenswood,  W.  Va. 

Hennepin,  111.  Ray,  N.  D. 

La  Salle,  111.  Summerfield,  Ohio. 

Lincolnton,  N.  C.  Wyandotte,  Ok. 


THE  WORK  OF  RUNNING  WATER  (Continued) 


IV.  THE  TOPOGRAPHIC  DEVELOPMENT   OF 
REGIONS  BY  STREAMS 


I.  ASSIGNMENT 


a)    Topographic  Maps 
Abbieville,  S.  C. 
Anthony,  Kan. 
Arnoldsburg,  W.  Va. 
Boonville,  Ind.       . 
Brownsville,  Pa. 
Burlingame,  Kan. 
Casselton,  N.  D. 
Cleveland,  Ohio. 
Coldwater,  Kan. 
Covington,  Ohio. 
Dawson  Springs,  Ky. 
Emporia,  Kan. 
Fargo,  N.  D. 
Foxburg,Pa. 
Jbredoma,  Kan. 
Grundy,  Va. 

Henry  Mountains,  Utah. 
Lancaster,  Wis. 
La  Sal,  Utah. 


La  Salle,  111. 
Lincolnton,  N.  C. 
Madison,  W.  Va. 
Marshall,  Mo. 
Maxwell,  Cal. 
Mount  Mitchell,  N.  C. 
Mt.  Trumbull,  Ariz. 
New  Haven,  111. 
Niagara,  N.  Y. 
Oberlin,  Ohio. 
Owensboro,  Ind. 
Peytona,  W.  Va. 
Pickens,  S.  C. 
Pisgah,  N.  C. 
Prince  Frederick,  Md. 
Princeton,  Ind.  ^ 
Saylersville,  Ky. 
St..Croix  Dalles,  Wis. 
Tell  City,  Ky. 


H.  OUTLINE  FOR  STUDY 

*1.  Choose  five  maps  showing  regions  in  a  youthful  stage 
of  development,  and  state  why  they  were  chosen. 
2  17 


18  STUDIES  IN  GEOLOGY 

2.  In  what  stage  of  erosion  is  the  Niagara  region  ? 
*3.  Draw  a  cross-section  profile  across  the  Fargo  sheet 
along  the  parallel  46°  50'.     (Horizontal  scale,  same  as  that 
of  map;  vertical  scale,  J  inch  =  20  feet.)     Is  this  the  profile 
of  youth,  maturity,  or  old  age  ? 

4.  What  are  the  various  map  evidences  of  maturity  of 
topography  ? 

*5.  From  the  maps,  choose  one  region  which  shows  as 
nearly  ideal  maturity  as  possible,  and  list  its  essential 
characteristics. 

6.  Choose  three  other  regions  in  maturity  as  shown  by 
the  maps. 

*7.  Which  is  in  the  later  stage  of  development,  the  Prince 
Frederick  region  or  the  Brownsville  region  ?  Give  reasons 
for  your  answer. 

8.  Why  are  the  valleys  deeper  in  the  Mt.  Mitchell  region 
than  in  the  Lancaster  area? 

9.  Why  are  the  valleys  east  of  the  Blue  Ridge  (Pisgah 
sheet),  such  as  the  valleys  of  Middle  Saluda  River  and  the 
upper  part  of  South  Saluda  River,  deeper  than  the  valleys 
just  west  of  the  Blue  Ridge? 

*10.  The  stage  of  erosion  shown  by  the  Kansas  sheets  ? 
Reasons  ? 

11.  Choose  several  regions  represented  on  the  maps 
which  are  in  topographic  old  age,  and  from  them  work  out 
the  various  map  evidences  of  old  regions. 

*12.  Draw  a  cross-section  profile  across  the  Princeton 
sheet  along  parallel  38°  25'.  (Horizontal  scale,  same  as  that 
of  map;  vertical  scale,  J  inch  =20  feet.)  Compare  this  pro- 
file with  that  of  questi  on  3 .  What  is  the  essenti  al  difference  ? 

13.  Describe  briefly  the  general  topography  of  (a)  the 
Kentucky-Virginia  region,  (b)  the  Kansas  region,  and  (c) 


STUDIES  IN  GEOLOGY  19 

the  South  Carolina  region,  as  shown  by  the  maps  of  these 
states,  setting  forth  features  of  similarity  and  difference. 

*14.  Which  of  the  regions  mentioned  in  13  is  most  advanced 
in  the  present  cycle  of  erosion? 

*15.  Would  the  difference  in  the  stage  of  erosion  alone 
account  for  the  differences  between  the  Anthony  region,  and 
the  Grundy  region  ? 

*16.  Classify  ten  of  the  maps  of  the  assigned  list,  which 
have  not  been  used  in  answering  any  of  the  questions  above, 
as  to  the  stage  of  erosion  they  show. 

17.  What  features  in  the  area  shown  on  the  St.  Croix 
Dalles  sheet  are  not  due  to  stream  erosion  ?  How  does  the 
topography  shown  on  the  greater  portion  of  this  map  differ 
from  a  normal  erosion  topography? 

*1S.  Is  a  larger  proportion  of  the  surface  of  a  region 
available  for  agricultural  purposes,  in  youth,  maturity,  or 
old  age  ?  Consider  both  regions  of  slight  and  of  great  relief. 
Find  illustrations  on  the  maps  supporting  your  answer. 

19.  Note  the  location  of  common  roads,  railroads,  towns, 
and  general  density  of  population  in  the  several  regions. 
Has  the  stage  of  erosion  any  influence  on  the  above? 

20.  a)   Compare  the  region  shown  on  the  Arizona  sheets 
with  that  on  the  Ohio  sheets,  as  to  the  stage  of  erosion. 

b)  What  are  the  main  differences  between  the  topog- 
raphies of  the  two  regions  ?     Explain  the  differences. 

The  following  sheets  show  the  various  stages  of  erosion 
well,  and  may  be  made  the  basis  of  further  work: 
Anson,  Tex.     ;/  Cataldo,  Id. 

Bidwell  Bar,  Cal.  Columbiana,  Ala. 

Burlington,  Kan.  Corazon,  N.  M. 

Butler,  Mo.  3^,  Cranberry,  N.  C. 


20  STUDIES  IN  GEOLOGY 

Caldwell,  Kan.  Cross  Plains,  Wis. 

Cumberland,  Ohio.  Mt.  Pines,  Cal. 

Danville,  Ill.-Ind.  New  Harmony,  Ind. 

Delphos,  Ohio.  Oxford,  Ohio. 

Dublin,  Ohio.  Palmyra,  Mo. 

Elizabeth,  111.  Ray,  N.  D. 

Fayetteville,  W.  Va.  Rochester,  N.  Y. 

Forsyth,  Mo.  Sansbois,  Ok. 

Hennepin,  111.  Summerfield,  Ohio. 

Leavenworth,  Kan.  Tallula,  111. 

Marseilles,  111.  Tarboro,  N.  C. 

Masontown,  Pa.  Uhrichsville,  Ohio. 

Maumee  Bay,  Ohio.  Vermilion,  Ohio. 
Wartburg,  Tenn.JI 


THE  WORK  OF  RUNNING  WATER  (Continued) 


V.  THE  INFLUENCE  OF  INEQUALITIES  OF  HARD- 
NESS AND   ROCK  STRUCTURES  ON  EROSION 
TOPOGRAPHY  AND  STREAM  ADJUSTMENT 

I.  ASSIGNMENT 


a)  Topographic  Maps 

Antietam,  Md. 
Boonville,  Ind. 
Bright  Angel,  Ariz. 
Cucamonga,  Cal. 
Denver,  Colo.  yO 
Fort  Payne,  Ala. 
Hamburg,  Pa. 
Harrisburg,  Pa. 
High  Bridge,  N.  J.  * 
Holyoke,  Mass.  ^L 
Jonesville,  Ky. 
Kaaterskill,  N.  Y. 

b)  Geologic  Folios 

Bristol,  Va. 
Franklin,  W.  Va^Va. 
Livingston,  Mont. 


Lancaster,  Wis. 
Mesa  de  Maya,  Colo. 
Monadnock,  N.  H. 
Mountain  Home,  Idaho. 
Mt.  Taylor,  N.  M. 
Patoka,  Ind. 
Niagara,  N.  Y. 
Saypo,  Mont.  <// 
Sutter,  Cal. 
The  Dells,  Wis. 
Uvalde,  Tex.  */ 
Walsenburg,  Colo. 

Piedmont,  W.  Va. 
Rome,  Ga.  "  *" 


II.  OUTLINE  FOR  STUDY 

*1.  Draw  a  diagram  showing  the  attitude  of  the  strata 
between  Golden  and  Denver  (Denver  sheet),  across  South 
Table  Mountain. 

21 


22  STUDIES  IN  GEOLOGY 

*2."  Make  a  comparative  study  of  the  arrangement  of  the 
drainage  lines  on  the  Lancaster  and  Saypo  sheets.  Explain 
the  differences. 

*3.  a)  Explain  the  conditions  of  rock  hardness  and  rock 
structure  shown  on  the  Niagara  sheet. 

b)  The  possible  origin  of  the  cliff  through  Queenston 
and  Lockport  ? 

c)  Outline  the  history  of  Niagara  Falls  in  as  much 
detail  as  may  be  from  the  map. 

d)  Under    what     conditions     would     Lake    Erie    be 
drained  by  Niagara  River  as  the  falls  continue  to  recede? 

4.  The  origin  of  Sherrill  Mound  (S.  central  rectangle)  and 
Sinsinawa  Mound  (S.  E.  corner),  Lancaster  sheet? 

5.  What  is  the  significance  of  the  fact  that  the  Mumford 
Hills  (Patoka  sheet)  have  the  same  elevation  as  the  high  land 
southeast  of  them  ? 

*6.  Draw  a  cross-section  of  the  Susquehanna  valley  at  the 
first  narrows  above  Harrisburg  (Harrisburg  sheet),  and 
another  two  miles  below  the  narrows.  (Horizontal  scale, 
same  as  that  of  map;  vertical  scale,  J  inch  =  50  feet.) 
Interpret  these  sections. 

7.  Choose  two  areas  shown  on  the  assigned  maps  where 
the  underlying  rocks  are  probably  massive. 

*8.  Does  topography  developed  by  erosion  give  (In  all 
cases  ?  In  some  cases  ?)  the  data  necessary  for  determin- 
ing structure?  How?  Illustrate  by  determining  inferen- 
tially  the  structure  of  ten  regions  shown  on  the  maps. 
Give  reasons. 
9.  Rome  folio: 

*a)  Show  with  drawings  how  the  direction  of  dip  of 

tilted  beds  may  be  determined  from  the  topographic  sheet. 

b)  In  what  direction  do  the  strata  of  which  Taylor 


STUDIES  IN  GEOLOGY  23 

Ridge  (N.  W.  and  N.  central  rectangles)  is  composed, 
probably  dip  ? 

c)  The  probable  structure  between  Simms  Mountain 
and  Lavender  Mountain  ? 

d)  Test  conclusions  of  b)  and  c)  by  reference  to  section 
BB  of  the  structure  section  sheet. 

e)  From  the  topographic  map,  determine  the  probable 
origin  of  Gaylor  Ridge  (W.  central  rectangle).     According 
to  the  historical  geology  sheet,  are  the  rocks  which  make 
up  this  ridge  of  such  a  character  as  to  resist  successfully  the 
processes  of  erosion  ?     See  also  section  CC  of  the  structure 
section  sheet. 

f)  Study  other  ridges  and  valleys  of  the  topographic 
map  in  connection  with  data  given  on  the  historical  geology 
and  structure  section  sheets. 

g)  Note  the  numerous  faults  shown  on  the  historical 
geology  and  structure  section  sheets.     Could  their  presence 
have    been    detected    from    the    topographic    map    alone  ? 

10.  Note  the  relation  between  valleys  and  faults  as  shown 
on  the  geologic  map  of  the  Livingston  folio.  See  also 
Iddings,  Jour.  GeoL,  Vol.  12,  1904,  pp.  94-105. 

*11.  a)  What  structure  is  suggested  by  the  topography  of 
the  region  between  Pine  Mountain  and  Cumberland  Moun- 
tain, Jonesville  sheet? 

b)  Is  further  adjustment  of  streams  likely  to  occur  in 
the  southeastern  part  of  this  area? 

12.  What  structure   will   explain   th,e  .  curving    form    of 
Cushetunk  Mountain,  High  Bridge  sheet  ? 

13.  Piedmont  folio: 

a)  From  the  topographic  sheet,  determine  whether 
the  strata  are  horizontal  or  tilted.  If  different  in  different 
parts,  state  the  facts. 


24  STUDIES  IN  GEOLOGY 

/  b)  Test  the  conclusion  arrived  at  in  a)  by  reference 

to  the  areal  geology  and  structure  section  sheets. 

c)  On   the  topographic   sheet,   find   features   which 
*  seem  to  be  due  to  rocks  harder  than  their  surroundings. 

d)  From  the  areal  geology  sheet,  see  what  sort  of 
^/rock  makes  the  features  designated  in  c),  and  what  kinds  of 

rock  are  adjacent  to  it. 

,  e)   Is  it  possible  to  tell  from  the  topographic  sheet  in 

what  directions  the  various  strata  dip  ? 

f)  As  shown  on  the  areal  geology  sheet,  do  the  main 
streams  flow  parallel  with  the  folds,  or  at  right  angles  to 
them? 

j  g)  Are  the  main  valleys  located  on  the  synclines  or 

on  the  anticlines   (see  structure  sections)  ?     Explain   why 
this  should  be  so. 

14.  a)  Study    the    various    maps    of    the  Franklin   and 
^   Bristol  folios  for  the  various  influences  of  unequal  resis- 
tance of  rocks  and  rock  structures  on  erosional  topographies 
and  on  stream  adjustment. 

b)  As  seen  on  the  structure  section  sheet  (Franklin 
folio),  is  the  Stc  formation  resistant  or  non-resistant  to 
erosion  ?  From  the  legend  of  the  areal  geology  sheet,  note 
the  character  of  the  rock  of  this  formation. 

*15.  On  each  map  of  the  assigned  list,  find  topographic 
features  which  may  be  referred  primarily  to  inequalities  of 
hardness.  This  includes  depressions  as  well  as  elevations. 

16.  How  may  elevations  due  to  superior  hardness  of  rock 
be    distinguished    from    elevations    of    other    origin,    e.g., 
volcanic  cones?     To  what  sorts  of  cases  is  your  answer 

«  applicable  ? 

17.  At  what  stage  in  the  development  of  an  erosion  cycle 
are  outcrops  of  hard  rock  most  conspicuous  topographically  ? 


STUDIES  IN  GEOLOGY  25 

Further  work  on  the  subjects  considered  in  this  exercise 
may  be  based  on  the  following  maps: 

Abajo,  Utah.  Flintstone,  Md. 

Abingdon,  Va.  Fort  Collins,  Colo. 

Bellefonte,  Pa.  Hollidaysburg,  Pa.  4-  *- 

Bisuka,  Idaho.  Loon  Lake,  N.  Y. 

Cumberland  Gap,  Ky.  Loveland,  Colo. 

Delaware  Water  Gap,  Pa.  Monticello,  N.  Y. 

Elizabethtown,  N.  Y.  Morrillton,  Ark. 

Elmoro,  Colo.  Natural  Bridge,  Va. 

Emmitsburg,  Md.  Sallisaw,  Ok. 

Everett,  Pa.  Sansbois,  Ok. 

Passaic,  N.  J. 


THE  WORK  OF  RUNNING  WATER  (Continued) 

VI.  CYCLES  OF  EROSION 

I.  ASSIGNMENT 


a)    Topographic  Maps 

\|a    Antietam,  Md. 

£  Arnoldsburg,  W.  Va. 


,! 

/  Batesville,  Ark 
' 


.  * 


Belief  onte,  Pa.  < 

Delaware  Water  Gap,  Pa. 
Boonville,  Ind. 
Bright  Angel,  Ariz. 
Corazon,  N.  M. 
Echo  Cliffs,  Ariz. 
Elizabeth,  111. 
Everett,  Pa. 
Forsyth,  Mo. 
Hamburg,  Pa.         ^1 
Harrisburg,  Pa.  ; 
Harrodsburg,  Ky. 

Walsenburg, 


Holyoke,  Mass. 
Lockport,  Ky. 
Marshall,  Ark. 
Mountain  View,  Ark.  f  t 
Mt.  Taylor,  N.  M. 
Palo  Pinto,  Tex. 
Passaic,  N.  J. 
Pawpaw,  Md. 
Sallisaw,  Ok. 
Sansbois,  Ok. 
San  Francisco   Mt., 

Ariz. 

Tusayan,  Ariz. 
Tuscumbia,  Mo. 
Wausau,  Wis>7 
Colo. 


II.  OUTLINE  FOR  STUDY 

[  *1.  Account  for  the  marked  difference  in  the  upper  and 
lower  portions  of  the  valley  of  the  Little  Colorado,  San 
Francisco  Mt.  and  Echo  Cliffs  sheets.  Draw  a  profile 

26 


STUDIES  IN  GEOLOGY  27 

to  scale  of  the  stream  bed  from  "The  Crossing"  to  the 
Colorado  River.  (Horizontal  scale,  same  as  that  of  map; 
vertical  scale,  J-  inch  =  250  feet.) 

*2.  Draw  cross-sections  of  the  upper  and  lower  portions 
of  the  valley  of  the  Little  Colorado.  (Horizontal  scale, 
same  as  that  of  map;  vertical  scale,  J  inch  =  250  feet.) 

3.  a)  Study  the  cliffs  and  terraces  on  the  Bright  Angel 
sheet  for  suggestions  of  more  than  one  cycle  of  erosion. 

b)  Is  it  likely  that  all  the  terraces  are  due  to  uplift  of 
the  land  ?     How  many  uplifts  would  be  called  for  ? 

c)  Is    the    most    extensive    terrace    (forming    rim    of 
Granite    Gorge)  probably  due  to  the  rejuvenation  of  the 
stream  by  uplift  ? 

d)  What  other  explanations  may  there  be  for  these 
terraces,  besides  successive  uplifts  ? 

*4.  Is  there  any  difficulty  in  distinguishing  true  intrenched 
meanders  of  a  stream  in  the  second  cycle,  from  consequent 
crooks  in  the  first  cycle  of  erosion  ?  How  would  the  former 
differ  from  the  latter  ?  Apply  the  criteria  to  the  Tuscumbia 
region;  to  Conondoquinet  Creek,  Harrisburg  sheet;  to 
the  Arnoldsburg  region;  to  Brazos  River,  Palo  Pinto  sheet. 
5.  Can  you  suggest  any  conditions  which  may  have 
caused  the  Connecticut  River,  Holyoke  sheet,  to  flow  across 
the  hard  beds  of  the  Holyoke  Range,  when  a  course  a  few 
miles  to  the  west  would  have  avoided  them  ? 

*6.  Antietam  sheet: 

a)  Strata  horizontal  or  tilted  ? 

b)  The  origin  of  the  ridges  ? 

c)  Explain  how  Potomac  River  came  to  flow  across 
the  ridges. 

d)  Draw     a     profile,     to     scale,     from     Sharpsburg 
(northwest    part    of    map)    southeast    to    Petersville. 


28  STUDIES  IN  GEOLOGY 

e)  Interpret  the  above  profile. 

f)  Name    the    evidences    of  more  than  one  cycle  of 
erosion  shown  on  this  map.     Are  they  conclusive  ? 

*7.  Draw  a  profile  along  the  meridian  of  76°  50'  on  the 
Harrisburg  sheet.  (Horizontal  scale,  same  as  that  of  map; 
vertical  scale,  -J-  inch  =  400  feet.) 

*8.   Give    possible    interpretations    of    the    above    profile. 

9.  What  are  the  possible  interpretations  of  the  terraces 

shown  on  the  mountain  slopes  of  the  Everett  quadrangle? 

*10.  Using  the  Pennsylvania  maps  as  types,  work  out  the 
erosional  history  of  this  part  of  the  Appalachian  Mountain 
region  in  detail. 

11.  When  in  the  erosional  history  of  the  Appalachian 
Mountains  wTere  the  great  notches,  or  narrows,  developed  ? 

12.  How  many  cycles  of  erosion  are  shown  on  the  Arkan- 
sas sheets,  and  how  are  they  recognized  ? 

*13.  How  many  cycles  of  erosion  are  suggested  by  the 
topography  shown  on  the  Wausau  sheet  ? 

14.  Work  out  the  probable  erosion  history  of  the  region 
around  the  Ditney  Hills  on  the  Boonville  sheet. 

*15.  a)  From  the  Elizabeth  sheet,  draw  a  cross-section 
profile  through  "o"  of  "Brown  "  (Brown  School)  (Sec.  5, 
T.  28  N.  R.  4E.),  and  "M"  of  "  Benton  Mound"  (W.  Sec. 
27,  T.  28  N.  R.  4  E.).  (Horizontal  scale,  same  as  map; 
vertical  scale,  £  inch  =  20  feet.) 

b)  After  a  careful  study  of  the  rest  of  the  map  and 
of  the  profile  above,  give  more  than  one  possible  interpreta- 
tion of  the  erosional  history  of  the  region. 

c)  How   would   you   work  in  the  field  to  discover 
the  correct  interpretation  ? 

*16.  What  seems  to  have  been  the  erosion  history  of  the 
New  Mexico  region  ? 


STUDIES  IN  GEOLOGY  29 

1 7.  What  is  the  probable  history  of  the  numerous  mesas 
and  buttes  shown  on  the  Tusayan  quadrangle  ? 

18.  Work  out  the  probable  erosion  history  of  the  Okla- 
homa region,  so  far  as  illustrated  by  the  Oklahoma  maps. 

19.  What  data  beyond  those  furnished  by  the  topographic 
maps  would  be  needed  for  working  out,   with  certainty, 
the  erosion  history  of  the  regions  shown  on  these  maps  ? 

20.  Are  topographic  features  not  in  any  way  connected 
with  the  history  of  erosion  cycles  likely  to  be  mistaken  for 
those  which  result  from  uplift  ?     If  so,  what  ? 

*21 .  What  evidence  would  you  look  for  in  the  field  to  prove 
the  existence  of  an  old  base-level  plain,  or  an  ancient 
peneplain  ? 

The  maps  given  below  show  various  evidences  of  more 
than  one  cycle  of  erosion,  and  may  be  used  for  further  work 
on  this  subject: 

Apishapa,  Colo.  Lykens,  Pa. 

Dawson  Springs,   Ky.  Madison,  W.  Va. 

Flintstone,  Md.  Mesa  de  Maya,   Colo. 

Franklin,  Pa.  Nashville,  Tenn. 

Hancock,  Wr.  Va.  Natural    Bridge,    Va. 

High  Bridge,  N.  J.  Peytonia,    W.  Va. 

Hollidaysburg,  Pa.  Ravenswood,  W.  Va. 

Hummelstown,  Pa.  Somerville,  N.  J. 

Huntingdon,  Pa.  1/7  Versailles,  Mo. 

Latrobe,  Pa.  Wvandotte.  Ok. 


THE    WORK    OF    RUNNING    WATER  (Continued) 

VII.  STREAM  PIRACY 
I.  ASSIGNMENT 


a)  Topographic  Maps 

Abingdon,  Va.  Harpers  Ferry,  Va. 

Bellefonte,  Pa.  Kaaterskill,  N.  Y.  L 

Canyon,  Wyo.  Lancaster,  Wis. 

Emmitsburg,  Md.  Meadows,  Idaho. 

Fayetteville,  W.  Va.  Mt.  Jackson,  Colo. 

Flintstone,    Md.  Natural  Bridge,  Va. 

Fort  Payne,  Ala.  Saypo,  Mont. 

b)  Geologic  Folios 

Chattanooga,  Tenn.^  '  Piedmont,  W.  Va.-Md. 6' 

Franklin,  W.  Va.-Va.  Pikeville,  Tenn. 

II.  OUTLINE  FOR  STUDY 

1.   Describe  a  possible  case  of  future  piracy  in  the  Canyon 
region. 

*2.  Work  out  in  writing  a  rational  explanation  of  the  valley 
flats  along  the  main  and  side  streams  just  north  of  Dubuque, 
Lancaster  sheet.  The  essential  points  are  Couler  Valley, 
Peru  Bottoms,  and  the  Little  Maquoketa  River. 

*3.  Describe  two  cases  of  piracy  shown  on  the  Kaaterskill 
sheet. 

4.  Show  why  conditions  for  piracy  are  favorable  in  the 
Saypo  region. 

30 


STUDIES  IN  GEOLOGY  31 

*5.  Find  a  "wind  gap"  in  the  Harpers  Ferry  region,  and 
trace  its  history. 
6.  Pikeville  folio: 

a)  Note  the  location  of  the  Sequatchie  River  and  its 
relation  to  the  geology  of  the  region. 

b)  Is  it  probable  that  the  present  course  of  the  river 
is  its  original  course  ?     If  not,  how  may  its  present  course 
have  been  attained? 

c)  Is  any  change  in  its  course  likely  to  occur  in  the 
future  ? 

d)  What  are  the  chances  of  the  Sequatchie  stealing 
water  now  flowing  north  into  Caney  Forks  ? 

*7.  Chattanooga  folio: 

Study  the  northwestern  quarter  of  the  topographic  map 
for  possible  piracies  not  yet  accomplished.  Point  out  specific 
illustrations  and  give  reasons  why  piracy  is  likely  to  take 
place.  (Use  geologic  map,  structure  sections,  and  text.) 

8.  Piedmont  and  Franklin  folios: 

a)  Study  the  drainage  of  the  southeast    quarter   of 
the  Piedmont  topographic  sheet,  and  the  northeast  part  of 
the  Franklin  sheet  down  to  the  South  Branch  River. 

b)  Study  the  same  area  on  the  Areal  Geology  Sheet. 

c)  Read  the  text  on  "Topography  and  Drainage," 
p.  1,  Piedmont  folio. 

*d)  Point  out  the  possibilities  of  future  piracy  in  this 
area. 

9.  In  what  stage  of  erosion  is  piracy  most  likely  to  occur? 
Illustrate   from   several   of  the  assigned  maps  which  show 
regions  in  different  stages  of  erosion. 

10.  Study  the  remaining  topographic  maps  of  the  assign- 
ment for  cases  of  piracy  already  accomplished  or  liable  to  be 
accomplished  in  the  future. 


32  STUDIES  IN  GEOLOGY 

The  following  topographic  maps,  most  of  which  are  of 
recent  date,  also  show  possible  cases  of  piracy: 
Antietam,  Md.  Loveland,  Colo. 

Cranberry,  N.  C.  Montpelier,  Idaho. 

Fort  Collins,  Colo.  Peytonia,  W.  Va. 

Franklin,  Pa.  Ravenswood,  W.  Va. 

Grand  Teton,  Wyo.  Shoshone,  Wyo. 

Jonesville,  Ky.  Uhrichsville,  Ohio. 


THE    WORK     OF    RUNNING    WATER  (Continued) 

VIII.  STREAM  DEPOSITION 
I.  ASSIGNMENT 

a)    Topographic  Maps 

Baton  Rouge,  La.  Lexington,  Neb. 

Boonville,  Mo.  Lockport,  Ky. 

Bridgeport,  Cal.  Marshall,  Mo.  & 

Cucamonga,  Cal.5-  Marysville,  Cal. 

David  City,  Neb.  Montrose,  Colo. 

Donaldsonville,  La.  Morrillton,  Ark.  ,?6 

Eish  Springs,  Utah.  Mt.  Whitney,  Cal. 

Fulton,  Mo.  New  Orleans,  La. 

Gibson,  La.  Parker,  Ariz. 

Glasgow,  Mo.  San  Jose,  Cal.  ajr 

Hahnville,  La.  3  7  Savanna,  la. 

Hawthorne,  Nev.  Sierra ville,  Cal.^£ 

Hermann,  Mo.  Silver  Peak,  Nev. 

Independence,  Mo.  St.  Louis,  Mo.  ?: 

Jefferson  City,  Mo.  Tacoma,  Wash.  3( 

Lexington,  Mo.  Van  Horn,  Texas. 
Watkins,  N.  Y.  3 

II.  OUTLINE  FOR  STUDY 

1.  What  suggestions  are  there  on  the  Fish  Springs,  Silver 
Peak,  Sierraville,  and  Marysville  sheets  that  the  lowlands 
are  covered  with  waste  from  the  mountains? 

*2.  If  the  lowlands  referred  to  in  1  are  covered  with  loose 
material,  how  would  you  go  to  work  in  the  field  to  determine 
3  33 


34  STUDIES  IN  GEOLOGY 

whether  this  material  is  of  marine,  lacustrine,  or  river 
origin  ?  If  lacustrine,  how  would  you  determine  whether 
from  fresh  or  salt  water? 

3.  Explain  the  behavior  of  the  streams  on  the  lowlands, 
referred   to    in    1. 

4.  What  distribution  of  coarse  and  fine  material  would  be 
found  in  these  lowlands  if  they  are  covered  by  material 
wrashed  from  the  higher  lands  ? 

*5.  Why  are  there  only  isolated  fans  on  the  east  side  of 
Owens  Valley,  Mt.  Whitney  sheet,  while  a  piedmont  alluvial 
plain  has  been  formed  on  the  west  side? 

*6.  How  do  alluvial  fans  differ  from  ancient  deltas  ? 

7.  a)  Study  the  various  deposits  at  the  foot  of  the  moun- 
tains shown  on  the  Hawthorne  sheet. 

*b)  How  could  it  be  told  in  the  field  from  the  deposits 
east  and  southeast  of  Walker  Lake,  whether  that  lake  was 
formerly  larger  and  deeper  than  now  ? 

*8.  Would  a  vertical  section  through  the  lowlands,  Cuca- 
monga  sheet,  just  south  of  San  Antonio  Canyon,  and  every- 
where equidistant  from  the  foot  of  the  mountains,  show 
material  of  uniform  coarseness  ?  Reasons  ?  How  would 
the  material  of  such  a  section  compare  with  that  of  a  section 
at  right  angles  to  the  foot  of  the  montains  ?  Reasons? 

9.  Note  the  course  of  the  washes  below  the  mouth  of 
Deer  Canyon  and  Day  Canyon,  on  the  Cucamonga  sheet. 
*Explain   how   this   process   aids   in   forming   a   piedmont 
alluvial  plain. 

10.  Lexington  sheet: 

a)  Explain  the  network  of  streams  in  the  channel  of 
the  Platte  River. 

b)  What   is   the    probable   explanation    of   the   hills 
about  six  miles  northwest  of  Lexington  ? 


STUDIES  IN  GEOLOGY  35 

c)  In  view  of  the  fact  suggested  by  a),  account  for 
the  high  gradient  of  the  Platte  River. 

11.  Arrange  the  Missouri  sheets,  so  as  to  show  the  con- 
tinuous course  of  the  Missouri  River: 

a)  Is  deposition  now  in  progress?     The  evidence? 

b)  Is  deposition  going  on  more  rapidly  at  the  up- 
stream or  the  down-stream  ends  of  the  islands?     Explain. 

c)  How  are  the  various  lakes  on  the  flood  plain  to  be 
accounted  for  ? 

*d)  Evidences  that  the  river  has  shifted  its  course  ? 
Where  are  other  shifts  likely  to  occur? 

*e)  In  what  ways  may  the  general  difference  in 
width  of  the  flood  plain  above  and  below  Glasgow  be 
accounted  for? 

f)  Has  the  difference  in  topography,  and  the  con- 
dition of  the  tributary  streams  above  and  below  Glasgow, 
any  bearing  on  the  problem  ? 

*g)  Explain  why  the  Wakenda,  Grand,  and  Chariton 
Rivers  flow  parallel  with  the  main  after  entering  the  valley, 
h)  Why  are  there  fewer  roads  on  the  flood  plain  than 
on  the  upland  ? 

i)  Explain  what  determined  the  location  of  Miami, 
DeWitt,  Cambridge,  Glasgow,  Saline  City,  Lisbon,  and 
Arrow  Rock. 

12.  a)  Explain  the  extremely  steep  slopes  of  the  walls  of 
the  valley  of  Kentucky  River,   Lockport  sheet,   not  now 
touched  by  the  river,  such  as  those  west  of  Polsgrove  and 
east  of  Craddock  Bottom. 

b)  Explain  the  curved  cliff  and  flat  east  of  Bethel 
Church  (south  central,  and  southeast  rectangles). 

*13.  Explain  the  form  and  distribution  of  the  higher  land 
shown  on  the  Louisiana  sheets. 


36  STUDIES  IN  GEOLOGY 

14.  Note  the  alluvial  deposits  northeast  from  Nita  Crevasse 
(  Donaldson  ville  sheet). 

*15.  Draw  a  cross-section  to  scale  along  the  parallel  of 
40°  5',  on  the  Donaldsonville  sheet.  (Horizontal  scale,  same 
as  that  of  map;  vertical  scale,  J  inch  =  20  feet.)  Interpret 
the  section. 

16.  Interpret  the  flat  at  the  south  end  of  Seneca  Lake, 
Watkins  sheet. 

*17.  What  sort  of  deposit  would  you  expect  to  find  underly- 
ing the  city  of  Tacoma,  Tacoma  sheet  ? 

*18.  Why  does  Wapato  Creek  flow  independently  to  the 
sea  in  the  valley  of  Puyallup  River,  Tacoma  sheet? 

19.  Point  out  the  various  advantages  commercially  in  the 
situation  of  Tacoma. 

20.  Examine   the   remaining   flood    plain    maps   of   the 
assignment  for  illustrations  of  stream  deposition. 

Other  maps  which  show  well  various  phases  of  stream 
deposition  are  the  following: 

Atchison,  Kan.  Lac  des  Allemands,  La. 

Bonnet  Carre,  La.  La  Sal,  Utah. 

Cheniere  Caminade,  La.  Loveland,  Colo. 

Chico,  Cal.  Montpelier,  Id. 

Cut-off,  La.  Pasadena,  Cal. 

Durango,  Colo.  Patoka,  Ind.-IH. 

East  Delta,  La.  "  '  Paxton,  Neb.  3  <° 


Fort  Collins,  Colo.  Portland, 

Fort  McKinney,  Wyo.  Quarantine,  La, 

Fremont,  Neb.  Ray,  N.  D. 

Gothenburg,  Neb.  Sacramento,  Cal. 

Grand  Teton,  Wyo.  San    Antonio,     Cal. 

Hamilton,  Mont.  San   Bernardino,    Ca). 

Kansas  City,  Kan.  San   Francisco,    Cal. 


STUDIES  IN  GEOLOGY  37 

San  Luis,  Cal.  Tarrytown,  N.  Y. 

Savanna,  la.  Three  Forks,   Mont.^ 

St.  Barnard,  La.  Watrous,  N.  M. 

Stromsburg,  Neb.  Waukon,   la.  ^^^ 

Syracuse,  N.  Y.  Williamstown,  N.  C.  3  ? 

The  following  charts  of  the  Mississippi  River  Commission1 
may  also  be  studied  to  advantage  in  connection  with  stream 
deposition : 

Sheets  9,  14,  19,  20,  and  27. 

Index  Charts  I,  II  and  III. 

The    following    Coast    Survey    Charts    are    also    good: 

Numbers  190,  191,  192,  194,  195    (fit  together),  and  19. 

1  These  charts  may  be  had  of  the  Mississippi  River  Commission, 
St.  Louis,  Mo. 


THE  WORK  OF  RUNNING  WATER  (Continued} 

IX.     STREAM  TERRACES 
I.  ASSIGNMENT 

a)    Topographic  Maps 

Bright  Angel,  Ariz.  Hennepin,  111. 

Chelan,  Wash.  La  Sal,  Utah. 

Cleveland,  Ohio.  Lockport,  Ky. 

Cohoes,  N.  Y.^  Marseilles,  111.  3 

Cordova,  la.— 111.  Mountain  Home,  Idaho. 

East  Cincinnati,  Ohio.  Mt.  Trumbull,   Ariz. 

-Elk  Point,   S.   D.  Point  Pleasant,.  W.Va. 

Foxburg,  Pa.  St.  Paul,  Minn. 

Harrisburg,  Pa.  Waukon,  la. 

Hartford,  Conn.^  West  Cincinnati,   Ohio. 

H.  OUTLINE  FOR  STUDY 

*1.  Draw  a  cross-section  to  scale  across  the  Illinois  River 
valley,  Marseilles  sheet.  How  may  the  feature  brought 
out  in  the  diagram  be  explained  ? 

2.  a)  What  has  probably  been  an  important  factor  in 
locating  Vermilion,  on  the  Elk  Point  sheet  ? 

b)  Note  and  explain  the  location  of  Fulton  and  Clinton, 
Cordova  sheet. 

*3.  Lake  Chelan,  Chelan  sheet,  probably  was  made 
chiefly  by  the  erosive  work  of  a  glacier.  It  drains  into 
Columbia  River.  Explain  the  formation  of  the  terraces 
along  the  river. 

38 


STUDIES  IN  GEOLOGY  39 

4.  Cleveland  sheet: 

a)  The  probable  origin  of  the  terrace  on  which  the 
city  of  Cleveland  stands  ? 

b)  The  elevation  of  the  area  around  Brooklyn  ?     Same 
for    the    area    3-6    miles    south    of    Brooklyn  ?     Explain. 

c)  Notice    the    several    terraces    along   the  Cuyahoga 
River.     What  is  the  elevation  of  these  terraces  above  the 
river?     State  possible  causes  for  the  terraces.     What  re- 
lation  might   there   be   between   the  terraces  and  different 
stages  in  the  level  of  the  lake  ? 

d)  Explain  the  isolated  patch  of  terrace  at  ThoTnburg 
(central  rectangle). 

*5.  Draw  a  cross-section  from  the  5000-foot  contour  on 
Smith  Prairie,  Mountain  Home  sheet,  due  southwest  to  the 
same  elevation  on  the  southwest  side  of  the  Boise  River. 
Interpret  the  section. 

*6.  How  many  terraces  are  shown  in  the  valley  of  the 
Connecticut  River  on  the  Hartford  sheet?  What  are  the 
heights  of  these  terraces  above  the  river  ? 

*7.  Compare  and  contrast  the  topography  of  the  lands 
between  200  feet  and  300  feet  in  altitude,  Cohoes  sheet, 
with  the  topography  of  the  land  above  300  feet.  Why 
the  differences  ?  How  might  your  hypothesis  be  tested  in 
the  field? 

8.  What  becomes   of  the  terraces  of  the  Hoosic  River, 
Cohoes  sheet,  when  traced  up-stream  ? 

*9.  Draw  a  profile  from  Mechaniosville,  about  six  miles 
east  northeast  to  the  second  "C"  in  word  "Schaghti- 
coke,"  Cohoes  sheet.  (Horizontal  scale,  same  as  that  of 
map;  vertical  scale,  J  inch  =  100  feet.) 

*10.  What  is  the  probable  origin  of  the  terraces  along  the 
above  profile  ? 


40  STUDIES  IN  GEOLOGY 

11.  What  suggestions  can  you  make  for  the  terraces  in  the 
Grand  Canyon,  as  shown  on  the  Arizona  sheets  ? 

12.  Trace  out  the  relationship  of  the  terraces  of  the  main 
and  tributary  canyons  in  the  Arizona  sheets. 

13.  Explain  the  terraces  of  the  Grand  and  Green  Rivers 
in  the  La  Sal  region.     What  becomes  of  these  terraces  up- 
stream ? 

14.  Waukon  sheet: 

a)  The    probable    origin    of    the    stream  terraces? 

b)  What  seems  to  have  determined  the  location  of 
Lansing,  Harpers  Ferry,  and  Prairie  du  Chien  ? 

15.  Locate  and  interpret  terraces  on  four  maps  of  the 
assigned  list,  not  designated  in  previous  questions. 

Stream  terraces  are  also  shown  to  good  advantage  on  the 
following  topographic  maps : 

Beaver,  Pa.  Newcastle,  Pa. 

Camas  Prairie,  Idaho.  Ottawa,  111. 

Covington,  Ohio.  Oxford,  Ohio. 

Delaware  Water  Gap,  Pa.  Peytona,  W.  Va. 

Diamond  Creek,  Ariz.  Ravenswood,  W.  Va. 

Fonda,  N.  Y.  Springfield,  Mass. 

Kaibab,  Ariz.  Tallula,  111. 

Latrobe,  Pa.  Tarboro,  N.  C. 

Mount  Adams,  Wash.  Urichsville,  Ohio. 

Wyandotte,  Ok. 


THE  WORK  OF  GLACIERS 

X.  MOUNTAIN  GLACIATION 

I.  ASSIGNMENT 

a)    Topographic  Mapx 

Bridgeport,  Cal.  Leadville,  Colo. 

Chief  Mountain,  Mont.^  Montrose,  Colo. 

Cloud  Peak,  Wyo.4<£  -<*  7  Mount  Stuart,  Wash. 

Cucamonga,  Cal.  Mt.  Jackson,  Colo. 

Gilbert  Peak,  Utah.  Mt.  Lyell,  Cal. 

Glacier  Peak,  Wash.  Mt.  Whitney,  Cal. 

Hamilton,  Mont.  Shasta  Special,  Cal.  ^ 

Hayden  Peak,  Utah.  '  Yosemite,  Cal.    n-** 

II.  OUTLINE  FOR  STUDY 

1.  Study  all  the  maps  of  the  assignment  for  the  results  of 
the  work  of  valley  glaciers  in  high  mountains. 

2.  Notice  the  elevation  necessary  for  present   and   past 
glaciation  in  different  latitudes. 

3.  What  are  the  various  map  evidences  of  the  former 
greater  extent  of  valley  glaciers  ? 

*4.  Explain  why  the  Sierra  Nevada  Mountains  (Mt. 
Whitney  and  Bridgeport  sheets)  contain  glaciers,  and  why 
the  San  Antonio  Mountains  (Cucamongo  sheet)  do  not,  and 
apparently  never  have. 

5.  Explain  the  distribution  of  the  glaciers  around  Mt. 
Shasta,  Shasta  Special  sheet. 

41 


42  STUDIES  IN  GEOLOGY 

*6.  a)  What  types  of  glaciers  are  shown  in  the  Shasta  and 
Glacier  Peak  regions  ? 

b)  What  evidences  are  there  that  the  glaciers  were 
once  longer  and  more  numerous  than  now  in  these  regions  ? 

*7.  List  all  the  evidences  of  the  previous  existence  of 
valley  glaciers  in  the  Mt.  Lyell  region.  (There  are  six  or 
seven  of  them.) 

8.  Cloud  Peak  sheet: 

*a)  Select  a  valley  on  the  Cloud  Peak  sheet  as  a  type  of 
stream  valleys  re-shaped  by  valley  glaciers,  and  draw  a 
cross-section  of  it  to  scale. 

*b)  Draw  a  profile  from  the  crest  of  the  divide  at 
Mather  Peak  (east  central  rectangle)  east  and  north  down 
the  bed  of  the  tributary  to  the  North  Fork  of  Clear  Creek. 
(Horizontal  scale,  same  as  that  of  map;  vertical  scale,  -fa 
inch  =  250  feet.)  Interpret  the  profile. 

c)  Locate  a  hanging  valley  on  the  sheet. 

9.  Leadville  sheet: 

*a)  Interpret  the  curving  ridge  just  west  of  the  Arkansas 
River,  2\  miles  west  of  Leadville. 

*b)  The  probable  origin  of  Twin  Lakes  ? 
*c)   Locate  a  good  cirque  on  the  map. 

d)  Note   the   location   and   elevation   of   the   cirques. 
Note  the  elevation  of  the  rim  above  the  cirques,  and  of  the 
botton  of  the  cirques.     Note  the  profiles  of  the  valleys  which 
have  cirques  at  their  heads. 

*e)  Draw  a  profile  of  the  bottom  of  Crystal  Lake 
Gulch  (southwestern  part  of  sheet)  from  the  south  edge  of 
the  map  to  Lake  Creek.  (Horizontal  scale,  same  as  that 
of  map;  vertical  scale,  -fa  inch  =100  feet.)  Interpret  the 
profile  and  explain  its  origin. 

f)    About  what  elevation  was  necessary  for  glaciation 
in  this  region  during  the  glacial  period. 


STUDIES  IN  GEOLOGY 


43 


10.  a)  Explain  the  formation  of  the  compound  cirques  in 
the  Hayden  Peak  and  Gilbert  Peak  regions. 

b)  How  much  of  this  region  appears  to  have  been 
above  the  ice  during  the  glacial  period? 

*11.  Why  are  depositional  features  not  so  noticeable  on 
maps  as  those  due  to  erosion  ? 


The  following  maps   may  be 
this  topic: 

Berners  Bay,  Alaska. 
Browning,  Mont. 
Chief  Mountain,  Mont. 
Colfax,  Cal. 
Coopers  Lake,  Mont. 
Copper  Mountain,  Alaska. 
Crandall,  Wyo. 
Dardanelles,  Cal. 
Dayton,  Wyo. 
Grand  Teton,  Wyo. 


used  for  further  work  on 

Ishawooa,  Wyo. 
Lake,  Wyo. 
Meadows,  Idaho. 
Mount  Adams,  Wash. 
Shoshone,  Wyo. 
Silverton,  Colo. 
Skykomish,  Wash. 
Snoqualmie,  Wash. 
Telluride,  Colo. 
Unita,  Utah. 


THE  WORK  OF  GLACIERS  (Continued} 

XI.  GENERAL  GLACIATION 

I.  ASSIGNMENT 

Topographic  Maps 

Boston,  Mass.        ^  Monadnock,  N.  H. 

Brooklyn,  N.  Y. 6  Muskego,  Wis.  - 

Delavan,  Wis.  Oconomowoc,  Wis. 

Durant,  Ia.^  Oelwein,  la. 

Fryeburg,  Me.  Palmyra,  N.  Y. 

Geneva,  Wis.  Paradox  Lake,  N.  Y.  y 

Gray,  Me.  Sodus  Bay,  N.  Y. 

Greenwood  Lake,  N.  J.  Staten  Island,  N.  Y. 

Islip,  N.  Y.  St.  Croix  Dalles,  Wis.  3 

Koshkonong,  Wis.  Stoughton,  Wis. 

Lancaster,  Wis.  Waterloo,  Wis.^ 

Madison,  Wis.  Weedsport,  N.  Y. 

Marion,  la.  Wheaton,  111. 

Minnetonka,  Minn.  Whitewater,  Wis.  ' 

II.  OUTLINE  FOR  STUDY 

*1.  From  the  maps  of  the  assigned  list,  select  at  least  five 
regions  where  the  dominant  type  of  topography  is  due  to 
ground  moraine. 

*2.  Locate  terminal  moraine  belts  on  at  least  five  sheets. 
3.  Work  out  the  main  topographic  differences  between 
ground  moraine  and  terminal  moraine,  using  as  a  basis  the 
maps  selected  in  1  and  2. 

44 


STUDIES  IN  GEOLOGY  45 

*4.  Locate  at  least  four  areas  which  are  inferred  to  be 
outwash  plains.  How  could  your  inference  be  tested  in  the 
field  ? 

5.  Find  drumlins  on  at  least  two  sheets. 

*6.  Contrast  the  Wisconsin  and  the  New  York  type  of 
drumlins. 

7.  Account  for  the  lakes  and  swamps  in  the  Dela van- 
Geneva  region. 

8.  Account  for  the  lakes  and  swamps  in  the  Paradox 
Lake  region. 

*9.  Determine  (inferentially)  by  topography,  the  direction 
of  ice  movement  in  the  Paradox  Lake,  Islip,  Palmyra,  and 
Brooklyn  regions.  How  could  your  inference  be  verified 
or  disproven  in  the  field  ? 

10.  The  probable  origin  of  Lake  Minnetonka,   Minne- 
tonka  sheet  ? 

*11.  Under  what  conditions  does  drift  control  the  topog- 
raphy of  a  region  ?  Illustrate  by  reference  to  maps  show- 
ing regions  where  (a)  drift  controls  the  topography,  and  (b) 
where  bed-rock  controls  the  topography. 

*12.  Select  examples  of  hills  which  may  be  kames,  so  far 
as  their  topography  and  surroundings  are  concerned. 

13.  Study  the  maps  for  examples  of  eskers  and  valley 
trains. 

*14.  Compare  and  contrast  the  Lancaster  and  Koshkonong 
areas  as  to  their  value  for  agricultural  purposes.  What  con- 
ditions due  to  glaciation  in  the  latter  are  (a)  advantageous, 
and  (b)  disadvantageous  to  agriculture  ?* 

15.  What  indications  of  glacial  erosion  are  shown  on  the 
maps  ?     Give  list  of  locations. 

*16.  Account  for  the  difference  in  the  topography  of  the 
northeastern  and  southwestern  portions  of  the  area  shown 
on  the  Oelwein  sheet. 


46  STUDIES  IN  GEOLOGY 

*17.  Select  maps  showing  regions  glaciated  by  one  of  the 
older  ice  sheets. 

18.  How  would  you  distinguish  in  the  field  whether  an  area 
has  been  covered  by  the  last,  or  by  one  of  the  earlier  ice  sheets  ? 

19.  To   what  extent  is  the  topography  of  the  following 
regions  due  to  glaciation: 

a)  St.  Croix  Dalles.  c)   Marion. 

b)  Gray.  d)  Paradox  Lake. 

20.  Locate  as  many  types  of  glacial  lakes  as  you  can 
identify  on  the  maps. 

*21.  Describe  briefly  what  sorts  of  material  you  would 
expect  to  find  at  the  following  places: 

a)  West    Hills    (west     part    of     Islip    quadrangle) 

b)  Central  Islip  (central  part  of  same  area). 

c)  East  Islip  (4  miles  south  of  central  Islip). 

d)  Baker  Hill  (east  central  rectangle,  Palmyra  sheet). 

e)  In  the  sharp  elevation  2J   miles  south  by  south- 
west of  Palmyra,  Whitewater  sheet. 

f)  The  ridge  in  south  central  Sec.  3,  three  miles  north- 
west of  Naperville,  Wheaton  sheet. 

22.  Enumerate  all  the  features  shown  on  the  maps  which 
indicate  glaciation.  Comparison  of  maps  showing  typical 
glacial  topography,  with  the  Lancaster  sheet  of  the  driftless 
area,  will  be  helpful. 

The  following  maps  may  be  used  for  further  study  of  the 
work  of  the  continental  ice  sheet  in  the  United  States : 

Baldwinsville,  N.  Y.  Canton,  N.  Y. 

Brandon,  Vt.  Cross  Plains.  Wis. 

Brockport,  N.  Y.  De  Smet,  S.  D. 

Calumet  Special,  Mich.  Des  Moines,  la. 

Canada  Lake,  N.  Y.  Eastport,  Me. 


STUDIES  IN  GEOLOGY  47 

Elizabethtown,  N.  Y.  Peterboro,  N.H. 

Elmira,  N.  Y.  Raquette  Lake,  N.  Y. 

Fulton,  N.  Y.  Raritan,  N.  J. 

Geneva-Racine,  Wis.  Redfield,  S.  D. 

Harlem,  N.  Y.  Rochester,  N.  Y.  ^ 

Hennepin,  111.  Santanoni,  N.  Y. 

Huron,  S.  D.  Shopiere,  Wis. 

La  Salle,  111.  Silver  Lake,  Wis. 

Loon  Lake,  N.  Y.  Swan  Island,  Me. 

Massillon,  Ohio.  Tipton,  la. 

Monticello,  N.  Y.  Tonawanda,  N.  Y.-^ 

Morris,  111.  Waterloo,  Wis. 

Northville,  S.  D.  Watertown,  Wis. 

Orland,  Me.  Wilmington,  111 
Wooster,  Ohio. 


THE  WORK  OF  GLACIERS  (Continued) 


XII.    DRAINAGE   CHANGES  DUE  TO  GLACIATION 
I.  ASSIGNMENT 


a)    Topographic  Maps 
Chelan,  Wash.  ^ 
Cooperstown,  N.  Y. 
Cordova,  la. -111. 
East  Cincinnati,  Ohio.b 
Elizabeth,  111. 
Elmira,  N.  Y.^ 
Fairfax,  la. 
Hammondsport,  N.  Y/ 


Penn  Yan,  N.  Y> 
Phelps,  N.  Y. 
Pingree,  N.  D. 
Rosendale,  N.  Y. 
Skaneateles,  N.  Y. 
St.  Paul.  Minn. 
Stehekin,  Wash. 
Syracuse,  N.  Y. (f" 


Masontown,  Pa.  (See  folio.)    Tully,  N.  Y. 


Watkins,  N.  Y. 

West  Cincinnati,  Ohio. 


Methow,  Wash.  <* 
Minneapolis,  Minn.* 
Monticello,  N.  Y. 
b)  References 

Bull.  13,  111.  Geol.  Surv. 

Prof.  Paper  60,  U.  S.  Geol.  Surv.,  Plates  CX-CXIX. 
Mono.  XLI,  PL  III,  U.  S.  Geol.  Surv. 
Masontown-Uniontown,  Pa.,  folio.  U^ 

H.  OUTLINE  FOR  STUDY 

1.  Study  the  Cordova,  la. -111.  sheet  for  possible  changes 
in  drainage,  in  connection  with  Bull.  13,  111.  Geol.  Surv. 

2.  Work  out  the  probable  effect  of  the  ice  on  the  drainage 
of  the  region  shown  on  the  Phelps,  Hammondsport,  and 
Penn  Yan  sheets. 

48 


STUDIES  IN  GEOLOGY  49 

*3.  Pingree  sheet: 

a)  To   what   extent   is  the   James   River  Valley  pre- 
glacial  ?     Post-glacial  ?     How  sure  are  you  of  your  answer  ? 

b)  Make  hypotheses  for  the   lower  and   more  inter- 
rupted bluffs  on  the  east  side  of  James  Valley  near  Jim  Lake. 
Can  the  real  explanation  be  determined  with  certainty  from 
the  map  ? 

c)  How  may  the  strearnless  valleys  shown  on  the  map 
be  accounted  for  ? 

4.  Tully  sheet: 

a)  Note  the  following  features : 

1)  The  convergence  of  all  the  valleys  and  tributary 
valleys  toward  the  south. 

2)  The   divide   between   north   and   south  flowing 
streams    at    points    1|   miles  northwest  of  Apulia  Station, 
and  2  miles  northwest  of  Tully  Center. 

3)  The  northward  flowing  courses  of  Onondaga  and 
Butternut  Creeks. 

*b)  Draw  a  profile  to  scale  from  Cardiff  (central 
rectangle)  to  Mud  Lake. 

*c)  With  the  points  in  a)  and  the  profile  in  b)  in  mind, 
and  after  a  careful  study  of  the  rest  of  the  map,  give  a 
rational  account  of  the  effects  of  the  glacier  on  the  drainage 
of  this  region. 

5.  The    probable    origin    of    Lake    Chelan     (Stehekin, 
Methow,  and  Chelan  sheets)  ? 

6.  a)  Fit  together  the  East  and  West  Cincinnati  sheets, 
and  read  the  discussion  of  the  area  on  p.  63,  of  Prof.  Paper 
60,  or  in  Mono.  XLI,  Pt.  Ill,  U.  S.  Geol.  Surv. 

*b)  List  the  main  events  in  the  history  of  the  region 
leading  up  to  the  present  drainage  system. 

7.  Work  out  the  drainage  change  which  has  taken  place 


50  STUDIES  IN  GEOLOGY 

in  the  area  shown  on  Plate  CXIX,  -Prof.  Paper  60,  or  see 
the  Masontown-Uniontown  folio. 
*8.  Minneapolis  and  St'.  Paul  sheets: 

a)  Account  for  the  discrepancy  in  size  and  stage  of  de- 
velopment between  the  valley  of  the  Minnesota  River,  and 
the   valley   of   the    Mississippi    River   above   Pike    Island. 

b)  How  explain  the  numerous  lakes  and  marshes  in  the 
Minnesota  and  lower  Mississippi  valleys  ? 

c)  Why  are  there  no  lakes  in  the  upper  part  of  the 
valley  of  the  Mississippi  in  this  region  ? 

d)  Are  St.  Anthony   Falls    (northeast   corner   Minne- 
apolis sheet)  of  post-glacial    or    pre-glacial    origin  ?     The 
same  for  Minnehaha  Falls  (southeast  of  Minneapolis,  St. 
Paul  sheet)  ? 

e)  Can  you  tell  from  the  map  whether  the  walls  of  the 
Mississippi  gorge  southeast  of  Minneapolis  are  of  solid  rock 
or  of  drift  ? 

f)  What  basis  is  there  in  the  recession  of  St.  Anthony 
Falls  from  an  original  position  at  Pike  Island,  for  an  estimate 
of  the  time  since  the  last  glacial  epoch  ? 

9.  Study  the  headwater  region  of  Apple  River,  as  shown 
in  the  northeast  portion  of  the  Elizabeth  sheet,  according 
to  the  outline  below.  Though  this  immediate  district  is  in 
the  driftless  area,  an  abundance  of  old  drift  is  found  just 
east  of  the  boundary  of  the  quadrangle. 

a)  Note   the   continuity  of  the   valleys   occupied   by 
South  Fork  and  West  Fork  of  Apple  River. 

b)  Note  the   angle   between  the  valley  occupied   by 
South  and  West  Forks,  and  the  main  valley  of  Apple  River 
at  Millville. 

c)  Why  is  the  valley  of  South  Fork  wider  than  that 
of  West  Fork? 


STUDIES  IN  GEOLOGY  51 

d)  Why  does  the  valley  of  South  Fork  become  wider 
to  the  southeast  (up-stream)  ? 

e)  Why  do  some  of  the  tributaries  of  South  Fork  form 
an  acute  angle  with  the   main   down-stream   rather  than 
up-stream  ? 

f)  Explain  the  canyon-like  appearance  of  the  valley 
of  Apple  River  for   several   miles   southwest   of   Millville, 
and  the  contrast  between  this  valley  and  the  valley  of  West 
and  South  Forks. 

*g)  Work  out  and  state  a  possible  drainage  change  in 

this  area,  which  will  explain  the  above-mentioned  features. 

*h)  How  would  you  investigate  the  area  east  of  this 

region  in  the  field,  to  prove  or  disprove  your  hypothesis? 

*10.  Work  out  in  as  much  detail  as  possible  two  distinct 

cases  of  drainage  change  due  to  glaciation,  not  included 

in  the  preceding  questions. 

The  cases  outlined  in  the  exercise  above  are  only  a  few 
illustrations  of  hundreds  of  changes  in  drainage  affected 
by  the  ice  in  the  northern  part  of  the  United  States.  Some 
other  maps  which  show  various  effects  of  glaciation  on 
drainage  are  listed  below: 

Antwerp,  N.  Y.  Elizabethtown,  N.  Y. 

Baldwinsville,  N.  Y.  Ellsworth,  Pa. 

Calumet  Special,  Mich.  Franklin,  Pa. 

Canton,  N.  Y.  Fryeburg,  Me. 

Chief  Mountain,  Mont.  Greenwood  Lake,  N.  J. 

Delavan  and  Geneva  Wis.       Henuepin,  111. 
Dells,   Denzer,  Briggsville,      Oriskany,  N.  Y. 
and  Baraboo,  Wis.     (See     Snoqualmie,  Wash.  ^ 
Bull  V,  Wis.  Geol.  and     Tower,  N.  D. 
_Nat.  Hist.  Surv.)  Waterloo,  Wis. 

Des  Moines,  la.  Weedsport,  N.  Y. 

Wyndmere,  N.  D. 


XIII.  SHORE-LINES 


I.  ASSIGNMENT 


a)    Topographic  Maps 
Atlantic  City,  N.  J.rf 
Barnegat,  N.  J. 
Brooklyn,  N.  Y. 
Calumet  Special,  Mich. 
Cape  May,  N.  J. 
Castine,  Me. 
Cayucas,  Cal.'-r 
Choptank,  Md. 
Coos  Bay,  Ore. 
Erie,  Pa/ ' 
Falmouth,  Mass.'7' 
Fair  view,  Pa. 
Freeport,  Me. 
Hay  wards,  Cal.^l 
Highwood,  111. 
Islip,  N.  Y. 

Wellfleet, 


La  Jolla,  Cal. 
*  Marthas  Vineyard,  Mass.   L 

Nantucket,  Mass,  it 

Ocean  City,  Md. 

Port  Orford,  Ore.  ?• 

Portland,  Me. 

Prince  Frederick,  Md. 

Provincetown,  Mass. 

Racine,  Wis. 

San  Francisco,  Cal.  72 

San  Mateo,  Cal.  7  *• 

Sandy  Hook,  N.  J.  n 

Sodus  Bay,  N.  Y.7- 

Tacoma,  Wash. 

Tamalpais,  Cal.  ^ 

Tolchester,  Md.  ^ 
Mass.  r*-?r 


b)  Cost  Survey  Charts: 

Nos.  19,  21,  103,  104,  105,  5100,  5143,  8089. 

c)  Lake  Michigan  Chart  No.  5. 

II.  OUTLINE  FOR  STUDY 

1.  Account  for  the  difference  in  the  cliffs  shown  in  the 
Fairview  and  Tamalpais  quadrangles. 

52 


STUDIES  IN  GEOLOGY  53 

2.  Find  illustrations  of  erosional  features  on  the  shore- 
lines shown  on  the  maps. 

3.  Locate  illustrations  of   (a)  bars,  (b)  spits,  (c)   hooks, 
and  (d)  barrier  reefs,  on  at  last  three  maps. 

4.  How  have  the  bars,  spits,  hooks,  and  reefs  located  in 
3,  been  built  above  high  tide? 

*5.  Provincetown  and  Wellfleet  sheets: 

a)  Work  out  the  probable  origin  and  history  of  Cape 
Cod.   (To  do  this,  study  the  general  topography  and  the 
shore-line  carefully.) 

b)  Account  for  the  difference  in  the  character  of  the 
coast  on  the  east  and  west  side  of  Cape  Cod.     Which  side 
is  in  the  later  stage  of  development  ? 

6.  Explain  in  detail  the  horizontal  configuration  of  the 
coast  shown  on  the  Port  Orford  sheet. 

7.  What  effect  do  the  waves  have  on  the  valleys  between 
the  shore  and  the  Chicago  and  Northwestern  Railroad,  in 
the  Highwood  region? 

*8.  Racine  sheet: 

a)  Work  out  a  rational  explanation  for  the  peculiar 
course  of  Pike  River. 

b)  Account  for  the  narrow  embayment  in  the  north- 
western part  of  the  city  of  Kenosha. 

9.  What  is  the  source  of  the  material  of  which  Sandy 
Hook  is  made  (Sandy  Hook  sheet)  ? 

*10.  How  may  Coatue  and  Coskata  Beaches  (Nantucket 
sheet)  be  accounted  for?  Work  out  an  explanation  of  the 
"Points"  (cusps)  on  the  inner  margin  of  Coatue  Beach. 

*11.  On  the  assigned  maps,  find  three  shore-lines  the  form 
of  which  is  due  to  submergence,  and  three  due  to  emergence. 
Reasons. 

*12.  If  the  terms  youth,  maturity,  and  old  age  are  to  be 


54  STUDIES  IN  GEOLOGY 

applied  to  shore-lines,  in  what  stage  of  development  would 
you  put  those  shown  on  the  (a)  Tolchester,  (b)  Atlantic  City, 
(c)  Highwood,  (d)  Freeport,  (e)  Cape  May,  and  (f)  Fair- 
view  sheets  ? 

*13.  a)  Select  at  least  four  maps  where  glaciation  has 
affected  the  coast. 

b)  How  has  glaciation  modified  these  coasts  ? 

c)  What  other  factors  may  have  helped  to  determine 
the  horizontal  configuration  of  these  coasts  ? 

*14.  Frame  a  hypothesis  which  might  explain  the  origin 
and  development  of  Presque  Isle  (Erie  sheet)  and  its  to- 
pography. (Do  not  neglect  the  wave-cut  cliff  bordering 
the  bay  on  the  south.) 

15.  Account  for  the   peculiar   course   of  Walnut   Creek 
(Erie  sheet)  and  the  great  variation  in  the  character  of  the 
valley. 

16.  How  may  the  broad  flat  lands  bordering  San  Fran- 
cisco Bay  be  accounted  for  ?     (Tamalpais,  San  Francisco, 
San  Mateo,  and  Hay  wards  sheets.) 

*17.  Does  wave  erosion  straighten  shore-lines,  or  make 
them  irregular?  Point  out  illustrations  on  maps  of  the 
assigned  list. 

*18.  Does  coast-deposition  make  coasts  straight  or  irreg- 
ular? Point  out  illustrations. 

19.  Is  the  effect  of  waves  and  shore  currents  to  simplify 
or  complicate  shore-lines?     Verify  your  answer  from  the 
maps. 

20.  What  determines  the  rate  of  development  of  shore- 
lines ?     Cite  illustrations  from  the  maps. 

*21.  Describe  in  detail  two  shore-line  regions  of  different 
types.  In  doing  this,  consider  the  following  points: 

a)  Are  the  shore-lines  due  to  deposition  or  erosion  ? 


STUDIES  IN  GEOLOGY  55 

b)  Are  the  islands   of  rock,   glacial   drift,   or  shore 
drift? 

c)  Has  the  coast  been  glaciated?  • 

d)  Has  diastrophism  affected  the  coast  ?     If  so,  which 
phase  of  diastrophism  ? 

e)  What  influence  on  the  coast  has  the  work  of  (1) 
wind,  (2)  rivers,  (3)  waves,  (4)  currents,  (5)  glaciers,  and 
(6)  organic  agencies  had  ? 

f )  Is  the  coast  young,  mature,  or  old  ? 

g)  The  probable  future  of  the  coast  ? 

Further  study  of  the  subject  of  shore-lines  may  be  based 
on  the  following  maps  and  charts: 

a)  Topographic  Maps 

Arroyo  Grande,  Cal.  Goleta,  Cal. 

Asbury  Park,  N.  J.  Hamlin,  N.  Y. 

Biddeford,  Me.  7  Muskegat,  Mass. 

Boston  Bay,  Mass.    '  Northport,  N.  Y. 

Copper  Mountain,  Alas.  Oceanside,  Cal.  ^ 

Deer  Isle,  Me.  &  '  Piney  Point,  Md. 

East  Delta,  La.  Riverhead,  N.  Y. 

Euclid,  Ohio.  n  San  Luis,  Cal. 

Ferry,  Ohio.  Sandusky,  Ohio. 

Geneva-Racine,  Wis.  Shelter  Island,  N.  Y. 

Stonington,  Conn. 

b)  Coast  Survey  Charts 

Nos.  110,  188,  201,  207,  210,  315,  5106,  5127. 


XIV.  DIASTROPHISM 


I.  ASSIGNMENT 


a)  Topographic  Maps 
Boston,  Mass. 
Castine,  Me. 
Choptank,  Md. 
Coos  Bay,  Ore. 
Diamond  Creek,  Ariz.  7  7 
Echo  Cliffs,  Ariz. 

Erie,  Pa. 
Fairview,  Pa. 
Fish  Springs,  Utah. 
Fredricksburg,  Va. 

b)  Geologic  Folios 
Bristol,  Va. 
Franklin,  W.  Va.-Va. 
Livingston,  Mont. 

c)  Coast  Survey  Chart  No  5100. 

d)  References 

Mono.  XI,  U.  S.  Geol.  Surv. 
Mono.  II,  U.  S.  Geol.  Surv. 

H.  OUTLINE  FOR  STUDY 

1.  Name   several   coastal   regions   shown   on   the   maps 
assigned,  which  appear  to  have  sunk  relative  to  sea  level. 

2.  Select  several  shore-lines  apparently  due  to  emergence 
from  the  sea. 

56 


Grand  Teton,  Wyo. 
Hawthorne,  Nev. 

*7  *7 

Honey  Lake,  Cal. 
La  Sal,  Utah. 
Mt.  Trumbull,  Ariz.  77 
Mt.  Whitney,  Cal. 
Oceanside,  Cal. 
Tolchester,  Md. 
Uvalde,  Texas. 
Van  Horn,  Texas. 

Piedmont,  W.  Va.-Md. 
Rome,  Ga. 


STUDIES  IN  GEOLOGY  57 

3.  Do  the  raised  shore-lines  on  the  Erie  and  Fairview 
sheets    necessarily    mean    diastrophism    in    this    region  ? 
Explain. 

4.  a)  Explain  how  glaciers  may  so  modify  a  coast-line, 
as  to  make  it  appear  to  have  sunk. 

b)  How  can  coast-lines  due  to  sinking  be  distinguished 
from  coast  lines  developed  by  glacial  erosion,  (1)  on 
topographic  maps,  (2)  in  the  field? 

*5.  Interpret  the  coastal  area  shown  on  the  Oceanside 
sheet.  The  essential  features  are  the  cliffs  and  ridges  back 
from  the  shore,  the  salt-water  lagoons,  and  the  varying 
character  of  the  valley  of  the  San  Luis  Rey  River. 

6.  Interpret  the  coastal  region  of  the  Coos  Bay  quadran- 
gle, so  far  as  due  to  diastrophism. 

*7.  What  seems  to  have  been  the  origin  of  Honey  Lake 
(Honey  Lake  sheet)  ?     (For  discussion  of  this  point,  see 
Russell,  Mono.  XI,  U.  S.  Geol.  Surv.,  p.  25  and  Plate  III.) 
8.  Mt.  Trumbull  and  Diamond  Creek  sheets: 

a)  Study  for  evidences  of  faulting.     (See  the  general 
account  of  this  region  by  Dutton,  in  Mono.  II,  U.  S.  Geol. 
Surv.) 

b)  The   probable  origin   of   Grand  Wash   Cliffs  and 
Hurricane   Ledge?  Note  the  relation  of  these  features  to 
each  other. 

c)  How  could  the  date  of  faulting  in  this  region  be 
determined  in  the  field  ? 

d)  Why  is  the  Grand  Canyon  east  of  the  Grand  Wash 
Cliffs  deeper  than  it  is  west  of  the  cliffs  ?  Bring  out  the 
influence  of  faulting  on  the  formation  of  the  Grand  Canyon. 

e)  Explain  the  asymmetric  appearance  of  the  valley 
south  of  Pierce  Ferry  (southwest  rectangle,  Mt.  Trumbull 
sheet). 


58  STUDIES  IN  GEOLOGY 

*9.  How,  otherwise  than  by  faulting,  might  Echo  Cliffs, 
Echo  Cliffs  sheet,  be  accounted  for? 

*10.  How  could  the  presence  or  absence  of  faults  along 
the  scarps  shown  on  the  Honey  Lake,  Mt.  Trumbull,  and 
Echo  Cliffs  sheets  be  proved  in  the  field  ? 

11.  Locate  features  which  are  probably  fault  scarps  on 
at  least  three  sheets  not  designated  in  previous  questions. 

*12.  Give  several  possible  explanations  for  the  highlands 
in  the  north  and  northwest  parts  of  the  Uvalde  region,  and 
the  lowlands  in  the  rest  of  the  area  shown  on  the  map. 

*13.  Study  the  structure  sections  of  the  Rome,  Bristol, 
Piedmont,  and  Franklin  folios,  for  folds  and  faults  brought 
about  by  diastrophism. 

a)  Are  these  features  the  result  of  tension  or  pressure  ? 

b)  In  what  direction  were  the  forces  applied  ? 

c)  What    influence    has    diastrophism    had    in    the 
formation  of  the  topography  of  these  regions  ? 

d)  The    faults  are  all   of  the  same  type;   are   they 
normal  or  reversed? 

e)  What  is  the  probable  fundamental  factor  in  the 
origin  of  forces  which  develop  such  folds  and  faults  as  are 
shown    in    these    sections? 

*14.  Explain  the  several  terraces  on  the  south  side  of  San 
Clemente  Island  (Coast  Survey  Chart  No.  5100)  and  their 
absence  on  the  north  side.  Notice  in  this  connection  the 
depths  of  the  water  around  the  island. 

For  further  study  of  the  topographic  results  of  various 
phases  of  diastrophism,  see  the  following  maps: 

Delaware  Water  Gap,  Pa.       Fort  Payne,  Ala. 

Fish  Lake,  Utah.  Granite  Range,  Nev. 

Fort  Collins,  Colo.  Hamilton,  Mont. 

Fort  McKinnev   Wvo.  Hinsdale,  Mont. 


STUDIES  IN  GEOLOGY  59 

La  Jolla,  Cal.  Piney  Point,  Md. 

Loveland,  Colo.  Sacramento,  Cal. 

Meadows,  Idaho.  San  Luis  Rey,  Cal. 

Montpelier,  Id.  St.  George,  Utah. 

Sheet   3,    Atlas    of  the  Tertiary  History  of   the  Grand 
Canyon   District,   U.   S.    Geological   Survey. 


XV.  VULCANISM 
I.  ASSIGNMENT 

Topographic  Maps 

Crater  Lake,  Ore.  ^  Mount  Taylor,  N.  M. 

Elmoro,  Colo.  Mt.  Lyell,  Cal.  % 

Henry  Mountains,  Utah.'   '    Mt.  Whitney,  Cal. 

Holyoke,  Mass.  San  Francisco  Mt.,  Ariz. 

Honey  Lake,  Cal.  Shasta,  Cal. 

La  Sal,  Utah.  Spanish  Peaks,  Colo. 

Lassens  Peak,  Cal.    "  Uvalde,  Texas. 

Marysville,  Cal.  "7  Walsenburg,  Colo. 

Monadnock,  N.  H. 

II.  OUTLINE  FOR  STUDY 

1.  What  are  the  various  map  evidences  of  the  previous 
existence  of  volcanoes  ?  Of  lava  intrusions  ? 

*2.  Locate  volcanic  cones  on  two  maps,  and  state  whether 
they  are  probably  made  of  lava  or  cinders. 

*3.  Distinguish,  as  far  as  possible,  between  lava  cones  and 
laccoliths  on  the  maps.  Use  several  illustrations,  and 
state  reasons  for  your  conclusions. 

4.  What  wrere  the  parts  of  vulcanism  and  of  diastrophism 
respectively,   in   the  making  of  Crater  Lake  (Crater  Lake 
sheet) . 
*5.  Spanish  Peaks  sheet: 

a)  The  probable  origin  of  the  high  lands  around  West 
Spanish  Peak? 

60 


STUDIES  IN  GEOLOGY  61 

b)  The  probable  origin   of  the   discontinuous   linear 
elevations  radiating  outward  from  West  Spanish  Peak  ? 

c)  Is  the  igneous  rock  of  this  district  harder  or  softer 
than  its  surroundings  ? 

*6.  Draw  a  diagram  showing  the  structure  which  permits 
the  sill  forming  the  Holyoke  Range  (Holyoke  sheet)  to 
outcrop  as  it  does. 

7.  To  what  extent  have  the  features  of  these  maps  due  to 
vulcanism  been  modified  by  erosion  ? 

*8.  Mt.  Taylor  sheet: 

a)  The  origin  of  the  San  Mateo  Mts.  ? 

b)  Give  several   possible  explanations   for  the  small 
conical  hills  south  and  southwest  of  Miller  P.  O. 

9.  Note  the  lakes  shown  on  the  central  and  east  central 
portions  of  the  Lassens  Peak  sheet.     They  are  for  the  most 
part  not  of  glacial  origin.     How  may  they  have  originated? 

10.  What  conclusion  can  be  reached  from  the  Mt.  Lyell 
sheet,  as  to  the  age  of  the  Mono  Craters  ? 

*11.  a)  Are  features  directly  due  to  vulcanism  likely  to  be 
confused  on  the  maps  with  those  of  other  origin  ?  Compare 
Monadnock  Mountain  (Monadnock  sheet)  with  Mt.  Shasta 
(Shasta  sheet). 

b)  What  part  may  vulcanism  have  played  in  the 
making  of  Monadnock  Mountain  ? 

12.  How  has  vulcanism  affected  the  topography  of  the 
Elmoro  and  Walsenburg  regions  ? 

Though  vulcanism  is  not  well  illustrated  on  topographic 
maps,  the  following  maps,  in  addition  to  those  assigned, 
show  direct  effects  of  vulcanism: 

Aba  jo,  Utah.  Terlingua  Special,  Texas. 

Modoc  Lava  Beds,  Cal.    Trinidad,  Colo. 
Mount  Adams,  Wash. 


XVI.  SPECIAL  STUDY  OF  THE  BARABOO  REGION, 
WISCONSIN 

The  region  around  Baraboo,  Wisconsin,  shown  on  the 
four  maps  of  the  assignment,  is  exceptionally  rich  in  geo- 
logic phenomena.  Though  detailed  work  in  the  field  is 
necessary  before  all  the  complicated  history  can  be  ascer- 
tained, still  many  important  features  can  be  worked  out 
from  the  topographic  maps,  to  varying  degrees  of  certainty. 
The  questions  below  are  asked  with  a  view  to  bringing  out 
the  history  of  the  region  only  so  far  as  it  can  be  interpreted 
from  the  maps.  Any  one  of  many  other  regions  might 
have  been  chosen  for  such  a  study,  the  Baraboo  region  being 
selected  for  present  uses  chiefly  because  it  is  well  known 
to  the  authors  and  to  some  of  their  students. 

I.  ASSIGNMENT 

a)  Topographic  Maps 

Baraboo,  Wis.  Denzer,  Wis. 

Briggsville,  Wis.  The  Dells,  Wis. 

b)  References 

Professional  Paper  60,  U.  S.  Geol.  Surv.,  PL  CXX 
and  pp.  64,  65. 

Bulletins  Nos.  V  and  XIII  of  the  Wisconsin  Geo- 
logical and  Natural  History  Survey  are  reports  on  this  region 
and  may  be  used  for  reference  if  they  are  available. 

H.  OUTLINE  FOR  STUDY 

1.  Note  the  location  of  the  region  and  its  boundaries. 

62 


STUDIES  IN  GEOLOGY  63 

2.  Note   the   location    of   this    region  with   reference  to 
that  of  the' 'Driftless  Area." 

3.  Point  out  the  most  conspicuous  topographic  features 
of  the  region. 

4.  Does  drift  or  bed-rock  control  the  larger  features  of 
the  topography  ? 

*5.  Point  out  topographic  features  due  to  bed-rock;  due 
to  drift. 

*6.  What  may  have  given  rise  to  the  ridges  on  opposite 
sides  of  the  valley  of  the  Baraboo  River,  in  the  central  part 
of  the  region  ?  These  ridges  are  known  as  the  North  and 
South  Ranges,  respectively. 

7.  Give  a  possible  explanation  for  the  fact  that  the  south 
side  of  the  South  Range  is  steeper  than  the  north  side. 

8.  Can  you  suggest  any  reason  why  the  North  Range 
should  be  narrower  than  the  South  Range  ? 

9.  Are  the  rock  strata  horizontal  or  tilted  in  the  area 
around  Leland  and  Denzer  on  the  Denzer  sheet,  and  north 
of  Reedsburg  and  west  of  Kilbourn  on  The  Dells  sheet  ? 

*10.  What  inferences  can  be  drawn  as  to  the  structural 
and  age  relations  between  the  different  formations  of  the 
region,  in  view  of  your  answers  to  questions  6  and  9  ? 

11.  In   what    topographic  feature  does  the  hardest  rock 
of  the  region  probably  show  itself  ? 

12.  The    probable  origin  of  Elephant's  Back  (3^  miles 
north  of   Kilbourn,  on  The  Dells  sheet)  ? 

*13.  Give  a  possible  explanation  for  the  several  flats  at 
about  1400  feet  elevation  on  the  South  Range,  as  3^  miles 
north  by  northeast  of  Denzer,  4  miles  southeast  of  North 
Freedom,  and  just  east  of  Devils  Lake. 

*14.  The  Baraboo  Narrows,  the  gap  in  which  Devils 
Lake  lies,  and  the  Narrows  of  the  Baraboo  River  at  Able- 


64  STUDIES  IN  GEOLOGY 

man,  are  .of  pre-glacial  origin.  The  present  course  of  the 
Wisconsin  River  from  the  upper  end  of  The  Dells  to 
Prairie  du  Sac  (Baraboo  sheet)  is  clearly  post-glacial. 
Study  the  three  gaps  mentioned,  with  a  view  to  determin- 
ing the  pre-glacial  drainage  system  of  the  region. 

a)  The  mode  of  origin  of  the  three  narrows  ? 

b)  Which  of  the  three  is  widest  ?    Narrowest  ? 

c)  Work   out   a   pre-glacial   drainage   system   which 
would  account  for  these  gaps. 

d)  Explain  how  streams  came  to  flow  across  the  hard 
rock  of  the  ranges.     In  answering  this,  use  your  answer  to 
question  13. 

e)  Does  the  fact  that  the  Devils  Lake  gap  is  curved, 
have  any  bearing  on  your  conclusion  in  d)  ? 

15.  Note   the   various    passes   of    drift    deposits   in   the 
region. 

16.  Using  the  terminal   moraine,   as   mapped   on  Plate 
CXX  of  Professional  Paper  60  as  a  beginning,  trace  the  ter- 
minal moraine  on  the  maps  to  the  north  boundary  of  the 
Briggsville  sheet  on  the  north,  and  to  the  Wisconsin  River 
above  Prairie  du  Sac  on  the  south. 

*17.  Give  the  main  topographic  differences  between  the 
area  west  of  the  terminal  moraine  and  that  to  the  east. 

*18.  Does  bed-rock  or  drift  control  the  topography  im- 
mediately north  and  east  of  Merrimac  ?  West  of  Lodi  ? 

19.  Give  possible  explanations  for  the  small  undrained 
depressions  on  the  outwash  plain  3  miles  north  by  north- 
west of  Baraboo.     What  term  is  applied  to  outwash  plains 
with  such  depressions  in  their  surfaces  ? 

20.  Locate  an  outwash  plain  on  the  maps,  not  shown  in 
Plate  CXX  of  Professional  Paper  60. 

*21.  Bring  out  the  influence  of  the  topography  on  the 
position  of  the  edge  of  the  ice  during  the  glacial  period. 


STUDIES  IN  GEOLOGY  65 

*22.  a)  State  all  the  ways  in  which  the  direction  of  the 
movement  of  the  ice  is  suggested  by  the  maps. 

b)  What  additional  evidence  might  be  found  in  the 
field,  which  is  not  shown  on  topographic  maps  ? 

*23.  Explain  the  probable  origin  of  Devils  Lake. 

24.  Is  there  any  reason  for  thinking  that  Devils  Lake 
was  higher  during  the  time  of  glaciation  than  now  ? 

25.  Compare  the  altitude  of  the  surface  of  Devils  Lake 
with  that  of  the  Baraboo  River  at  Baraboo,  and  with  that 
of  the  Wisconsin  River  at  Merrimac. 

26.  How  must  the  presence  of  the  ice  have  affected  4he 
Baraboo  River? 

*27.  How  could  the  answer  to  26  be  tested  in  the  field  ? 

28.  Give  a  possible  explanation  for  the  nearly  flat  land 
along  the  Baraboo  River  between  Baraboo  and  the  Baraboo 
Narrows. 

29.  The  probable  origin  of  the  marshes  north  of  the  Bar- 
aboo Narrows  ? 

*30.  Give  a  rational  explanation  for  the  narrowing  of  the 
Wisconsin  valley  at  The  Dells  above  Kilbourn.  Did  the 
ice  probably  have  anything  to  do  with  this  ? 

*31.  As  a  summary  of  questions  13-30,  describe  in  as 
much  detail  as  possible  the  great  change  in  drainage 
brought  about  by  glaciation. 

32.  How  extensively  has  the  surface  of  the  drift  been 
eroded  by  streams  since  is  was  deposited? 

33.  What  probably  becomes  of  the  water  which  flows  into 
and  falls  on  the  surface  of  Devils  Lake,  in  view  of  the  fact 
that  the  lake  has  no  surface  outlet  ? 

34.  Why  are  there  more  houses  between  Merrimac  and  the 
terminal  moraine  to  the  west,  than  in  the  district  around 
Denzer  and  Leland? 

5 


66  STUDIES  IN  GEOLOGY 

*35.  Note  the  number  of  houses  along  the  north-south 
road  leading  north  from  the  east  edge  of  Baraboo,  and 
compare  with  the  number  along  the  north-south  road  lead- 
ing south  from  Coon  Bluffs  (south  central  part  of  The 
Dells  Sheet).  Explain  the  difference. 

36.  Where  are  the  most  favorable  localities  for  farming 
in  this  region,  so  far  as  can  be  told  from  your  study  of  the 
maps  ? 

37.  Summarize  the  events  in  the  history  of  the  region, 
which  may  be  determined     with  at  least  some  degree  of 
certainty  from  a  study  of  the  maps.     Compared  with  the 
data  that  can  be  collected  in  the  field  and  the  interpretation 
of  history  recorded  by  these  data,  the  results  of  the  present 
study  are  slight. 

If  further  work  of  the  nature  of  this  exercise  is  desired,  it 
is  suggested  that  the  maps  of  the  student's  own  vicinity  or 
maps  of  some  area  in  which  he  is  interested  be  used  as  a 
basis.  Such  maps  may  be  used  instead  of  those  mentioned 
in  this  exercise.  It  is  not  necessary  that  all  students  use 
the  same  maps,  in  an  exercise  of  this  kind. 


XVII.  A  BRIEF  STUDY  OF  THE  PHYSIOGRAPHY 
OF  THE  UNITED  STATES 

This  exercise  is  meant  to  bring  out,  so  far  as  is  possible 
from  the  maps  used  in  this  course,  the  distinctions  between 
the  main  physiographic  provinces  of  the  United  States.  It 
must  be  recognized,  however,  that  no  more  than  an  intro- 
duction to  the  subject  is  attempted,  and  that  the  maps  used 
cover  only  a  very  small  part  of  each  province  to  be  studied. 

I.  ASSIGNMENT 

All  the  topographic  maps  used  in  this  course. 
Some  good  map  of  the  United  States,  showing  political 
boundaries. 

A  relief  map  or  model  of  the  United  States,  if  available. 

II.  OUTLINE  FOR  STUDY 

1.  The  following  are  the  more  important  provinces  of  the 
United  States,  the  divisions  being  made  so  far  as  possible 
into  distinct  physiographic  units : 

1)  The  Atlantic  Coastal  Plain. 

2)  New  England  and  Eastern  New  York. 

3)  The  Appalachian  Mountain  Province. 

4)  The  Cumberland-Alleghany  Plateau. 

5)  The  Lower  Mississippi  Basin.  . 

6)  The  .Upper  Mississippi  Basin. 

7)  The  Great  Plains. 

8)  The    Rocky    Mountains,    including   their    many 
ranges. 

67 


68  STUDIES  IN  GEOLOGY 

9)  The  Sierra  Nevada  Mountains  and  other  ranges 
near  the  Pacific  Coast. 

10)  The     Great     Basin,     including     the     Southwest 
Plateau. 

2.  Using  the  political  and  relief  maps  of  the  United  States 
mentioned   above,    arrange   all   the   topographic   maps   of 
this  course  into  10  groups  according  to  the  physiographic- 
divisions  given  in  1. 

3.  Select  two  or  three  sheets  which  represent,  as  well  as 
any,  the  type  of  topography  characteristic  of  each  province. 

*4.  Using  the  sheets  of  3,  and  referring  to  other  maps  of 
the  ten  groups  when  necessary,  describe  briefly  the  main 
physiographic  features  of  each  province,  the  principal  agents 
and  processes  which  have  developed  those  features,  and 
as  nearly  as  possible  the  sequence  of  events  in  the 
development  of  the  present  surface  of  each  province.  This 
question  may  be  answered  without  great  detail,  but  only 
after  a  thorough  study  of  the  maps. 

XVIII.  EXERCISE  FOR  REVIEW 

*  Make  as  complete  an  interpretation  as  possible,  of  each 
of  the  regions  shown  in  the  following  maps: 
Antietam,  Md.  Lakin,  Kan. 

Apishapa,  Colo.  Natural  Bridge  Special,  Va. 

Bridgeport,  Cal.  Passaic,  N.  J. 

Chief  Mountain,  Mont.  Sallisaw,  Ok. 

Hawthorne,  Nev.  Waterloo,  Wis. 


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